The verb can in English: its meanings, forms and examples of use. Using 'Can' in clear language for dummies

Modal verb can(can) and its form could(could) is the most common modal verb in English. We use it to show that we can, know how, are capable of doing something. In this article we will get acquainted with all the features of the modal verb can (could).

The first thing to remember is after can or could there must be another verb. After all, on my own can does not report an action, but only shows our attitude towards it: “I can do some action.” And after this “I can” it is necessary to add “I can do what?”: can dance(I can dance) can sing(I can sing), etc.

And the second thing that must not be forgotten is after can we don't put to: can speak English. We are accustomed to the fact that two verbs in English must be connected with each other using to: decide to drink coffee(decide to have coffee) or offer to go for a walk(offer to go for a walk). But modal can works without to.

We noted that this modal verb has two forms: can And could. We use these forms with any subject, both singular and plural.

My friend can speak Japanese. - My friend knows how speak Japanese.

My friends can dance salsa. - My friends can dance salsa.

What's the difference between can And could? Can used when someone knows how to do something at present, and could– when someone knew how to do something in the past, now, most likely, they no longer know how.

He can swim. - He can swim.

He could swim. - He knew how swim.

How to build a sentence with can (could)

In the table we clearly show how to use can in different types of sentences.

And in the question, as expected, the word order will be slightly different.

Let's look at a few features of use can:

• Can (could) is always between the subject and the predicate.
• To ask questions, we will simply reschedule can And could first place, there is no need to add anything else.
• Particle in negation not joins can (could), forming the shape cannot (could not). In colloquial speech we usually cannot reduce to can't (couldn't). By the way, cannot– this is the only modal that merges with the particle not when writing. Do you know how to pronounce it correctly? can't: /kɑːnt/ or / kænt/? There is a British variant of pronunciation - / /. And teacher Ronnie will teach you the American version of pronunciation in his video.

What does the modal verb can (could) mean?

The easiest way to understand the meaning is can (could) with examples. We express with can:

1. The mental or physical ability to do something.

   In this case can (could) is usually translated as “to be able”, “to be able to”.

   I can’t speak to you now but I can call you in the evening. – I can’t talk to you now, but I can call you in the evening.

   He could speak French. – He could speak French.

   Can you drive a car? - Can you drive a car?

2. Commonly accepted statements

We use can, when we want to show that some statement is true in most cases. Here we translate can as in "can".

The vacuum can frighten your cat. – A vacuum cleaner can scare your cat. (as a rule, cats are scared of vacuum cleaners, but not all)

In New York it can be difficult to rent an apartment. – It can be difficult to rent an apartment in New York.

Flowers can grow faster if they get a lot of sunshine. – Flowers can grow faster if they receive a lot of sunlight.

It should be noted that we do not use the form could to express this meaning.

3. Permission, request, prohibition.

   There are several patterns here: a request is usually conveyed through a question, permission through a statement, and a prohibition through denial. If we see a request or permission in a sentence, we translate can the verb “to be able”, the prohibition is most often translated by the word “impossible”.

   – Can I take your car for the weekend? – Can I borrow your car for the weekend? (request)
   – Yes, you can. - Yes you can. (permission)
   – But you can’t exceed the speed limit. – But you can’t exceed the speed limit. (ban)

   We can express our request using can And could. Both options are often used in speech, only such requests differ in the degree of politeness. Let's look at examples:

   Can you tell me where the nearest bus station is? – Can you tell me where the nearest bus stop is? (this kind of treatment is more typical if you are communicating with a person of the same age)

   Could you tell me where the nearest bus stop is? – Could you tell me where the nearest bus stop is? (this is a more polite question; more often the British will use this option in order to be as polite and courteous as possible in the conversation)

   With the help can we can not only ask for permission, but also propose something ourselves. To do this we use the question form.

   Can I offer you a cup of tea? – Can I offer you a cup of tea?

   Can I help you choose a dress for the party? – Can I help you choose a dress for the party?

   Look interesting video from the teacher Alex, in which he, to those already known to us can And could, added a verb may.

   • You can also learn about the features of the modal verb may in the article “”.
4. Surprise, doubt, disbelief.

   This function also has its own patterns: doubt and distrust are usually found in negative sentences, and surprise - in interrogative ones. The verb is translated can (could) in such cases with the words “really”, “can’t be”, “hardly”, “can’t believe”, “possibly”, “probably”.

   Can these shoes cost so much money? - Are these shoes really worth that much? (astonishment)

   He can't work all day round. - It can’t be that he works around the clock. (mistrust)

   Do you know that could is a past tense form can. But if we want to express doubt in the past, we use the form can't have.

   He can’t have fallen asleep at the meeting. “It’s impossible that he fell asleep during the meeting.”

   They can't have missed the last bus. “I can’t believe they missed the last bus.”

   If someone violated a prohibition or did not listen to advice, then you can reproach him for this, using the same verb can. There is, however, one peculiarity: such sentences are constructed in the form of a negative question.

   Can’t you just stop telling silly jokes to the guests? “Can you just stop telling stupid jokes to your guests?”

   Can't you get along with her friends? – Can’t you communicate normally with her friends?

Set expressions with the verb can (could)

Can (could) occurs in some established expressions. Here are a few of the most common ones:

1. Can’t (couldn’t) but do something– there was nothing left but.
   

   I couldn't but agree with him. “I had no choice but to agree with him.”

2. Couldn't help doing something- I couldn’t resist; couldn't help but.
   

   I couldn't help laughing. – I couldn’t help but laugh.

3. Can’t stand something/somebody– I can’t stand something/someone.
   

   I can't stand him. – I can’t stand him.

To make sure that the modal verb can (could) is well remembered by you, take the test and keep our convenient sign for yourself.

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Using the modal verb can (could)

In English there is a separate group of verbs - the modal verbs - modal verbs. Their list is headed by the modal verb can and its past tense form could. This verb is included in the school study of the basics of the English language from the first years of learning. Modal verbs are fundamentally different from other verbs in that they can be used independently and do not indicate any specific action or state.

Using a modal verb

The verb can in English means “to be able, to be able to, to be able”, respectively, “could, was able to, was able” in the past tense. This modal expresses the ability of the person - the subject of the sentence - to perform an action indicated by the infinitive, with which the modal verb is used:

• I can ski - I can ski.

In this case, the subject (I) can perform the action (ski) indicated by the main verb after the modal. Same as in other proposals:

• We can read - We can read.
• You can write - You can write.
• She could do it - She could do it (can in past tense)
• We could build this house - We could build this house (can in past tense)

This verb can express:

• general opportunity or ability: I can attend this lesson today - I can attend this lesson today. Or: She can go hiking in spring - She can go hiking in the spring;
• form of permission or prohibition: She can go to the shop - She can go to the store. Or: You cannot take this thing - You cannot take this thing;
• a polite request for something: Can you help me? - You can help me? Or: Can we help this woman? -Can we help this woman?

The indicated modal verb, like its brothers, has no forms plural and endings when forming sentences containing nouns or pronouns of the third person singular:

• Nick can - Nick can (can)
• Jane can - Jane can (can)
• children can - children can (can)
• we could - we could (were able to) (can in the past tense)
• they could - they could (were able to) (can in the past tense)

To compose an interrogative sentence, a modal verb (both in the present and in the past tense) does not require additional auxiliary verbs; it itself performs their entire function:

• Can you repeat this word? -Can you repeat this word?
• Could she make a bowl? - Could she make this bowl?

The modal verb “to be able, to be able, to be able” does not have the form of a participle, gerund, or infinitive. But if the construction of a sentence requires such a form, synonymous combinations are used to mean the ability or permission to perform any action: to be allowed, to be able to.

I"ll be able to come to your place in a week - I can come to you in a week.

That is, “I am capable and allowed to come to you in a week.” Here verbs with a translation similar to the modal verb are used.

If another verb follows a modal in a sentence, the particle to is not required between them. This rule applies to all modal verbs:

• I can hide my daybook - I can hide my diary.
• We can walk to the park - We can walk to the park.

Expressing surprise using a modal verb

Using this modal verb, you can express surprise, disbelief or doubt that the person - the subject of the sentence - actually performed the action indicated by the infinitive form with which the modal verb or its past tense form could is combined.

In this version, the modal verb is used only in interrogative or negative sentences:

• Can (could) she speak Spain so well already? - Can she really speak Spanish that well already?
• Can (could) you finish this big report already? - Have you really finished this big report?
• Can (could) she repair this car already? - Can she really fix this car already?

In a sentence after a modal verb, the infinitive occurs in different forms. If the action expressed by the infinitive refers to the present, a non-perfect infinitive (simple or continuous) is used.

If the specified action refers to the past, the perfect infinitive (simple or continuous form) is used:

• Could they have prepared their lessons so quickly? - Was she really able to prepare her homework so quickly?

In this form, the modal verb can, could does not express the time of action; it is shown by the infinitive following the modal verb.

In these examples it is in the indicative form, which expresses a lesser degree of doubt. Could, on the contrary, is a subjunctive form and expresses a greater degree of doubt in the sentence:

• I have a felling I know this woman. Could it be Mary Cary? - It seems to me that I know this woman. Is this really Mary Carey?

Modal verb forms

Modals are two forms of the same word: the first form is the present tense, the second is the past simple tense. Forms of the verb can in the present tense: in the affirmative form can, in the negative form cannot (abbreviated as can’t). The shortened form is used mainly for colloquial speech.

The past tense form is in the affirmative meaning could, in the negative meaning could not (abbreviated couldn’t).

This verb does not have a future tense form. Synonyms are used for it:

• In summer we’ll be able to swim on the other side of river - In summer we will be able to swim to the other side of the river.
• Our son will be able to read this lecture - Our son will be able to read this lecture.
• I’ll be able to come to your room in an hour - I can come to your room in an hour.
• I"ll be allowed to visit this museum - I am allowed (I can) visit this museum.
• You will be allowed to go another country for the weekend - You are allowed (you can) go to another country for the weekend.

But with the help of a modal verb you can make a sentence in the future tense:

• We can read this poem after this lecture - We can read this poem after this lecture.
• We can visit our grandmother after tomorrow - We can visit our grandmother the day after tomorrow.

Interrogative sentences are constructed very simply - the modal verb is placed first in the sentence and the result is a question instead of a statement, to which you can give a short or detailed answer:

You can speak English very well - Can you speak English very well? - No, I cannot speak English very well.

Can you speak English very well - Can you speak English very well? - No, I can't speak English very well.

Please note that the translation of the statement and question does not change, only the semantic load is changed and the intonation of the question is added.

You can play the piano - Can you play the piano? - Yes, I can play the piano

Can you play the piano - Can you play the piano? - Yes I can.

We could order a favorite meat in the restaurant - Could we order a favorite meal in the restaurant? - No, we couldn't

We could order our favorite food at the restaurant - We could order our favorite food at the restaurant? - No, we couldn't.

Repeat examples

Try to answer the questions and guess how to turn the question into a statement, using a modal verb in the past or present tense:

Can your sister play tennis? - Does your sister know how to play tennis?

Can you swim well? - Can you swim well?

Could you walk around the city alone? - Could you walk around the city alone?

Could your granny drive a car? - Did your grandmother know how to drive a car?

Could you write your book without helping friends? - Could you write your book without the help of friends?

Could you go to the theater yesterday? - Could you go to the theater yesterday?

The answers to such questions will be short versions using the appropriate form of the modal verb:

Yes, I can (Yes, I can) or No, I can’t (No, I can’t);

Yes, I could (Yes, I could) or No, I couldn't (No, I couldn't).

Past tense forms of the verb can

During the first language lessons at school, you are introduced to many words. This list includes past tense verbs in English. Children and adults learn the table in which they are listed by heart. But this table does not contain the modal verb being studied. This is another exception that you just have to learn by heart.

The past tense could can be used to express a polite request:

Could I have this pen, please? -Can I take this pen?

Could I open the window? - Can I open the window?

Could you close the door? -Can you close the door?

Could he have a cup of tea? -Can he have a cup of tea?

Past tense verbs in English

The verb can in English can form the past indefinite tense - The Past Simple Tense. Modal verbs of the past tense in English in the table.

Today we will begin to study the category of modality. It includes verbs that are not actions, but allow us to indicate shades of main events. With their help, the desire, possibility, prohibition or permission of the specified action is expressed. In today's lesson we will look at what and when the modal verb can is meant to mean in English. This is the most ambiguous and frequently encountered representative of this group in conversations. Let's consider its construction, application and other grammatical nuances.

In general, using this verb is not difficult, so even textbooks for children contain the principle of forming phrases with can. Of course, only the simplest designs are selected for children, but complicated combinations do not pose difficulties for older people.

Present tense

In an affirmative sentence, the compound predicate has the form “ can+ infinitive" It is important to note that in in this case Infinitives are always used without to.

• Nick can run fast– Nick can run fast.
• My sister can cook a cake –Mysistercanpreparecake.

The conjugation of the verb can in the present tense is the same for all persons of nouns and pronouns: it never changes its form and does not attach any endings. By meaning, this form of the verb can express events of the present or future (nearest).

• My relatives can meet me at the railway station tomorrow –Morelativeswill be ableTomorrowmeetmeonstation.
• She can call themtoday“She can call them today.”

Modal verbs do not require the participation of auxiliary words, since in essence they are themselves. Therefore, they create interrogative and negative contexts on their own.

In questions, the compound predicate is broken, and can moves to the beginning of the sentence. If the phrase contains special question words, then they always precede the modal word.

• Can you bring thebook? -Can you bring this book?
• When can they arrive to us? – When can they come to us?

To negate the main verb, can adds the particle not, forming the combination cannot or can’t for short. Pay attention to the continuous spelling of the official form.

• Mywife cannot drive acar— My wife doesn’t know how to drive a car.
• I can 't cook lambchops- I won't be able to cook lamb chops.

Sometimes the verb can is used in English to construct interrogative and negative phrases. They are used in colloquial speech, as they carry an emotional connotation.

• Can 't yourchild warm up foodinthemicrowave? – Can’t your child heat up food in the microwave?
• Can 't they send methefax? -Can't they send me a fax?

Past tense

Officially, grammar distinguishes three forms for this modal word.

We’ll keep silent about the subjunctive mood for now, since it is a very complex grammatical complex, but let’s look at the constructions of the past.

The past is characterized by all the same forms of constructions as in the present, only can is transformed into could. The modal is still the same for all persons and numbers.

• I could play basketballverywellwhenIwasateenager– I could play basketball very well when I was a teenager.
• Could he read whenhewasfive? – Did he know how to read when he was 5 years old?
• My friend could not (couldn't) pass the exam – MyFriendNotcouldpassexam.
• Couldn't 't she call me? “Couldn’t she have called me?”

Often in the past tense, instead of could, the verb manage is used (the ex. form is managed). Its meaning is “successful, successful.” Please note that in this case the infinitive will be used with the particle to.

• The exam was difficult but I managed to pass it –Examwasdifficult,Butto memanagedpasshis.
• She trained hard and she managed to break the world recordShea lot oftrained,Andatherhappenedbeatworldrecord.

Note that can and could are sometimes used in combination with the perfect infinitive, i.e. in combination can/could+ have+ participle II. We'll talk more about this a little later, when we discuss cases of use.

Future

The modal verb can in English cannot officially be used in the future tense, i.e. you cannot add will to it. Yes, you can use it to indicate shades of the future, as in Present Simple, but nothing more.

We can use can to refer to features that we already have but that we plan to use in the future. If, we're talking about about what we will only master or receive, then it is necessary to replace can with its equivalent to be able to. This expression translates as “to be able to do something” and can be used in all tense forms: past, presentand future.

• Myfather is able to solve anyproblem– My father is able to solve any problem.
• Jack was able to dial thenumberandcallthepolice– Jack was able to dial the number and call the police.

However, most often this combination is used to express future events.

• We will be able to move to Spain in three years –Wewe canmoveVSpainthrough 3 of the year.
• Nextyear I will be able to speak Englishfluently– Next year I will be able to speak English fluently .

The phrase to be able to can also be used to express a question or denial.

• Will you be able to pay forsecond vocational education? – Will you be able to pay for a second vocational education?
• They will not (won’t) be able to buy a new model of this car –TheywillNotVconditionbuynewmodelthiscars.

We looked at how the modal verbs can, could and to be able to are used in sentences different types. Now let's talk about their semantic meaning.

The verb can in English – when and why is it used?

In the preface to the material, we already noted that this verb is ambiguous. The table below will help us consider in detail all situations of its use. It also provides examples of constructions and their translation.

Modal verbs are those that characterize the responsibilities, capabilities, desires and necessity of action. They directly convey the speaker’s attitude to what is happening.
Despite the fact that modal verbs are strong and do not need to be used auxiliary verb, when constructing interrogative and negative sentences, they cannot be used independently without a semantic verb:

I cannot fly. - I can not fly.
You may go. - You can go.

In English, modal verbs are used independently only when they form a short answer, or the meaning of the statement is clear from the previous context in which semantic (weak) verbs are used:

- Can you read this?
- I can.

Most people cannot run as fast as animals, but some can.

In English for expression possibilities/impossibility or abilities/inabilities to do something, two modal verbs are most often used - can And may.

They do not change in persons and numbers, as evidenced by the absence of an ending -s- in the present simple tense, do not have all the usual forms for weak verbs (for example, the ending -ing) and do not require the help of an auxiliary verb do/ does/ did.

Can vs. May

Can And may have a meaning in Russian be able/ be able/ allow. It’s worth noting right away that in most cases they are not interchangeable. In the image accompanying the illustration of the article there is a saying:

Do as you may if you can’t do as you could.

This aphorism uses three modal verbs at once and all three will have different shades of meaning. The sentence itself is translated as follows:

Do as you are allowed, if you are prohibited from doing as you could.

There are certain criteria when choosing a particular verb.

Can has two forms in English - the present tense form and the past tense form could, which will also be used in the subjunctive mood.
However, in English it is possible to use a modal verb can in the future tense. In this case, it will be replaced by an equivalent verb to be able to do smth.

I can read English. - Present Simple
He thought he could do it alone.- Past Simple
I wish I could see it.
He told me he could have seen it earlier.- Perfect

She will be able to finish the painting in Summer.- Future

May used in English in the form of present and past tense might, which can also be found in sentences in the subjunctive mood.

May I come in?- Present Simple
They might come yesterday.- Past Simple
He might be at home.- Subjunctive mood (subjunctive mood)

Use of Can and May

Modal verb can has a wider range of applications compared to the verb may.

1. For expression ability or ability to do something use can:

I can swim. Can you?

2. Can also used to indicate possibilities(theoretical or according to some rules):

You can find it in any dictionary.
Russian Railways can change the fares seasonally.- Russian Railways may change tariffs depending on the season.

3. When prohibited used for something cannot (can't). You can also find prohibitions with may, but they will sound too “soft”:

You cannot talk too loud in the library.- You can't speak loudly in the library.
You may not talk loudly in the library.- You are not allowed to speak loudly in the library.

4. Request can be expressed through can or could. The latter in this case will have emphatically polite treatment:

Can you pass me some butter?
Could you pass me some butter?

5. When expressing surprise in interrogative sentences or reproach the narrative often uses a modal verb can. Its shape could will reflect the extreme degree of the condition:

How can you be so rude?- How can you be so rude?
You could tell me in the end.- In the end, you could have told me!

6. Cannot (can't) used to denote strong mistrust:

She can't work there.- Yes, she can’t work there.
They couldn't have done it.- They just couldn't do it.

Please note that in almost all cases of use could, verb emphasizes exaggerated attitude speaking to current events.

In situations where you ask permission to do something can be used both modal verbs. Offers with may at the same time they will sound more formally:

You can come in.- You can come in.
You may come in.- Come in./ You can come in.

Modal verbs may/might contain character speaker's uncertainty regarding the events described. As with could, past form might transmits greater degree of uncertainty:

Somebody's calling. It may be Mary.- Someone is calling. Perhaps it's Mary.
It may rain. Take an umbrella.- It can start raining. Take an umbrella.

Modal verb may most often used when especially polite treatment:

May I sit down?- Can I sit down? / Let me sit down?
Can I sit down? would rather be translated “Can I sit down?”

Often might used when expressing reproach. The sentence sounds especially caustic:

You might have told me beforehand.- I could have warned you in advance.

In this article we started a big important topic on modal verbs and talked about two of them. In future publications we will definitely try to highlight the remaining representatives of this category.

We wish you to be able to master this grammar material! May success be with you!

Victoria Tetkina

Modal verb can is one of the most common verbs in the English language. It is most often used when you need to express opportunity to take some action, in other words, to say “I can do this,” “he can,” “you can,” and so on. Verb could is the past tense form of the verb can, which we will also look at in this article.

Table: modal verb Can in affirmative, negative, interrogative form

• You can solve your problems later. - You can solve your problems later.
• We can watch this movie next time. - We Can watch this movie next time.

Also, instead of the verb can, the phrase will be able to can be used to denote a possibility in the future; read more about this below.

2. To express a request.

Are used can And could in interrogative form. A request with could sounds a little more polite; it is used in sentences addressed to another person (that is, not with the pronoun I).

3. To express a prohibition.

Verb can't often used to express a prohibition, that is, to say not “you cannot,” but “you are not allowed.”

4. To express surprise, doubt, disbelief.

There are many nuances here, much depends on the context.

Doubt with a tinge of mistrust is more often expressed in negative sentences with a verb in an indefinite form:

• He can't swim across Lake Tahoe. - Yes can not he swims across Lake Tahoe (distrust, doubt).

Surprise with a tinge of doubt and distrust is usually expressed in interrogative sentences with a verb in an indefinite form. In translation, the word “really” is often used to make the meaning clearer.

• Can this unicorn be real? – Really is this unicorn real?

If in the same question we use could the meaning will change a little. You'll get something like:

• Could this unicorn be real? – Could you this unicorn be real?

Often offers with can\could used ironically, with sarcasm, for example:

• Could do you buy more milk? -And you are even more milky could not buy?
• Could will you wake up any later? - And you are even later could not wake up?

But in this case great importance has intonation and context. One of the characters in the TV series “Friends,” Chandler, used similar phrases with “Could it be” so often that he was even sometimes imitated. Unfortunately, this feature of Chandler's speech was almost not reflected in the translation.

5. To express doubt about what happened

That is, I don’t believe that something happened. Scheme: cannot + have + Past Participle (affirmative or interrogative form).

The phrase is usually translated using “cannot be” or another suitable expression.

• He is my best friend, he cannot have betrayed me. - He is my friend, it can't be that he betrayed me.
• Billy doesn't have much money. He can't have bought this car. Billy doesn't have much money. He couldn't this car buy.
• Can she have forgotten to pick up the kids from house? – Really she I might have forgotten pick up children from home?

Revolution could have + Past Participle

Separately, we should consider the phrase could have + (past participle, third form of the verb). It may mean:

1. An action that someone could have done but did not

• She could have married him but she didn’t want to. - She could go out for him get married, but didn’t want to.
• They could have bought a house here 20 years ago but chose not to. - They could buy house here 20 years ago, but decided not to do it.

There is often a hint of reproach involved.

• You could have helped me instead of just sitting there. - You could help me instead of sitting here.
• I could have done more to help you. Sorry. - I could do more to help you. Sorry.

2. Assumption, guess about something that happened in the past

In this case, with a slightly different meaning, can be used may have or might have, cm. " ".

• Simon could have told her the truth. – Maybe, Simon told tell her the truth.
• They could have overheard what we said. – They could hear what we said.

In negation and question you can use can have + Past Participle, then you get a turn like “Really...?” or “It can’t be...”, discussed above (clause 5 “To express doubt about what happened”)

• Can she have forgotten about our meeting? – How could I she forget about our meeting?
• He can't have seen us. – Can't be so that he us saw.

3. Assumption about something that did not actually happen

This case belongs to one of the types of conditional sentences; read more about them in.

• I could have done well in my exam if I had worked harder. – I could have done better in the exam if I had prepared better.

Modal verb can and phrase to be able to

Verb can in the meaning of “to be able to do something” can be replaced by a synonymous phrase to be able to+ verb (to be able to do something). But there is a difference between these two ways of expressing possibility.

Can\to be able to in the future tense

It is usually said that turnover to be able to convenient to use when you need to talk about the possibility of doing something in the future, because the verb can there is no future tense form (you cannot say will can).

But here it is important to remember this nuance.

The verb can itself can refer to the future. For example:

• You can rest later. Now we have to work. - You you can(you can) rest later. Now we have to work.
• We can read this book tomorrow, let's play videogames. - We we can(we can) read this book tomorrow, let's play video games.

In the future tense, be able to is used when we talk about an opportunity, ability, or skill that does not exist now, but will appear in the future. The verb can cannot be used to express a possibility, an ability that will only appear in the future.

• Right: I will be able to walk properly after the surgery. - I I can Walking normally after surgery.
• Wrong: I can walk properly after the surgery.
• Right: will be able to work as a sailor. – When I finish these courses, I I can work as a sailor.
• Wrong: When I complete this training course, I can work as a sailor.

Both options, can or to be able to, can be used when talking about decisions or agreements related to the future:

• The doctor can\will be able to see you later today. - Doctor will be able see you later today.
• I can\will be able to help you with your homework later. - I I can help you with your homework later.
• I can\will be able to give you a lift home tonight. - I I can give you a ride home tonight.

Can\to be able to in the present tense

To be able to sounds more formal, even strange. It’s the same as saying in Russian not “I can play the guitar,” but “I’m capable of playing the guitar.”

• I can play a guitar. - I Can to play guitar.
• I am able to play a guitar. - I capable to play guitar.
• Michelle can can bake delicious pies.
• Michelle is able to bake delicious cakes. – Michelle capable bake delicious pies.

Variants with can are used much more often.

Can \ to be able to in the past tense

When talking about an ability or opportunity that existed in the past, both options can be used:

• When I was younger, I could could remember everything better.
• When I was younger, I was able to remember everything so well. – When I was younger, I could remember everything better.

Please note that in the past tense could usually means (in affirmative sentences) the ability to do something in general and is not used when talking about some one-time action at a certain moment. It makes more sense here to be able to.

• Right: We were able to visit Mary on Monday, because she wasn’t busy. - We were able to visit Mary on Monday because she was not busy.
• Wrong: We could visit Mary Monday, because she wasn’t busy.

IN negative sentences both couldn’t and wasn’t\weren’t able to can be used for both long-term actions and one-time ones.

• I couldn't / wasn't able to finish all my homework yesterday. - I could not finish homework yesterday.
• I couldn't / wasn't able to see the band at all from where I was standing. - I don’t really care wasn't visible(couldn't see) the musicians from where I was standing.
• I couldn't / wasn't able to drive when I was younger. - I couldn't drive, when I was younger.