The modal verbs can, could in English are the present and past tenses of the same modal verb (in English translate as "be able, able" or "could, could" in the past tense).
Verb singularity
The modal verb can has only two forms: the first form (can) for all pronouns and nouns of all persons, for the singular and plural for expressing the present tense, and the second (its derivative) - the verb could was used with all pronouns and nouns denoting the subject, all persons in the plural and singular only in the past tense. Another form of the verb could did not exist.
I could close the window. - I could close the window.
Kate could read this dull journal. - Kate could read this boring magazine.
They could speak japanese. - They could speak Japanese.
The difference between can and could
In addition to the fact that these two verbs are essentially two different forms of the same word in different time frames, there is another difference between them. The forms of the verb could in interrogative sentences express a more polite form of treatment. That is, the verb could in English is also a form of the subjunctive mood - Could you? - Could you? - Could you?
Could you close the window? “Could you close the window?”
Can you open the door? “Can you open the door?”
The second sentence raises the question of ability to perform an action. While in the first sentence on the potential for action. There is a difference and it is quite tangible.
Examples with the verb could:
Could you complete the task? “Could you complete this task?”
Could she cook the dinner? “Could she make dinner?”
Note:
- the English word dinner, which is translated as “lunch,” in colloquial English means “dinner,” but not in the home family circle;
- the “not” particle in the Russian translation of the sentences of examples does not mean negation, but indicates a more polite form of request.
Terms of use
1) The modal verbs can, could are primarily used to express the ability and ability to perform actions in physical activity.
Could the girls paint like that before they started to study at an art school? - Could girls draw like that before they began to study at an art school?
My cat could not climb a tree when it hurt the paw. - My cat (cat) could not (could) climb a tree when it damaged (a) its paw.
2) The verb could - past tense, but can use in the present tense, as already mentioned above, as a subjunctive mood.
Could you bring this notebook from the shelf? - Could you bring this notebook (notebook) from the shelf?
Could we stay here for the night? “Could we stay here for the night?”
3) When in the sentence the verb could precede a simple perfect tense, then we are talking about an event or action that was supposed to happen or happen, but did not happen and did not happen.
We could have asked him but we were late. - We could ask him, but we were late.
4) Negative sentences with could in English. Such sentences are based on the addition of the negation particle not to the form of the modal verb in the past tense.
They could not study at this university. - They could not study at this university.
She could not know the truth of this incident. - She could not know the truth about this incident.
My father couldn't come to this parental meeting. - My father could not attend this parent meeting.
5) Could also be used to give the sentence additional emotional coloring. In this color, the verb is used only in special matters and with the appropriate sentence infinitive and semantic verb forms, which also depends on the time frame.
What could we be doing this room? “And what can we do in this room?” (And what are we doing in this room?)
In this case, an emotional tone softens the strictly interrogative tone of the sentence.
Note:
- spoken English often uses short negative forms of the verb could not - couldn't.
Exercises
Verb can, could: exercises to repeat and consolidate the material.
1) In the first exercise, you need to insert the words within the meaning, following all the above examples and rules. Hint - consider translating a specific sentence to calculate the correct answer to the task. You have to choose between the options: could - couldn't - can - can't.
- In my second year as a teacher, I almost lost my self-confidence because I () teach anything. - In my second year of work as a teacher, I almost lost confidence in myself because I could not teach anything.
- Nick tried hard to persuade him friend but he () change her mind. - Nick tried his best to convince his friend that he could not change his mind.
- Mary says she () speak six languages ​​but she () talk to customers yesterday as she was a bit nervous. - Mary says that she can speak six languages, but she could not talk to customers yesterday, as she was a little nervous.
- Ted and her father () open the door because it was locked. “Ted and his father could not open this door because it was broken.”
- I () finally talk to Lisa after I tried to reach her on the phone for hours. - In the end, I could not talk to Lisa after I tried to call her on the phone for hours.
- You () memorize all of the rules in the past, you () do it now either. “You could remember all these rules in the past, and you cannot do it now.”
- My brother was the only one who () understand me, but now he () either. “My brother was the only one who could understand me, but now he cannot either.”
- Before the nuclear disaster in the 1943's, people () grow everything in their gardens. - Before the nuclear disaster in 1943, people could grow everything in their gardens.
- No matter how hard we try, we () see the difference in the two pictures our mother says she () easily see. - It doesn’t matter how hard we try, we can’t see the difference in these two pictures in which our mother can immediately see her.
- They () choose their opponents. The teams will be matched randomly. - They cannot choose their opponents (opponents). These commands are randomly selected.
2) Read the exercises carefully and try to determine which form of the modal verbs studied in this article can be omitted (). Note that the potential answer is already in parentheses. It is only necessary to understand whether it is correct or not. If not, what answer do you think is correct for each particular proposal?
- It was really scary walking through the forest at night! I (can't) see a thing, it was so dark!
- We (could) see from an early age that our daughter loved the water! She's a professional swimmer now.
- I would love to be brave enough to skydive, but I (can). I'm so afraid of heights.
- Of course you (can) bring your boyfriend to the party! He is very welcome.
- I (could) speak Japanese very well now as I learned the language when I was living there.
- (Couldn't) I finish work early today, please? I have a doctor's appointment I need to go to.
- Take your jacket with you. It (could) get cold later on.
Answers to the first exercise:
- couldn't.
- couldn't.
- can - couldn't.
- couldn't.
- could.
- could - can't.
- could - can't.
- could.
- can't - can.
- can't.
Answers to the second exercise with translation:
- Couldn't - It was very scary to walk through the forest at night. I could not see, it was so dark.
- From a very young age we could see that our daughter loves water. Now she is a professional swimmer.
- Can't - I wanted to be brave enough to parachute, but I can't. I am so afraid of heights!
- Of course you can take your boyfriend to the party. He will be welcome.
- C- I can speak Japanese very well since I learned this language when I lived there.
- Could - Can I finish the work earlier today, please? I have a doctor’s appointment, I need to go. (It is also appropriate to use the can form, but could in this situation fits perfectly, as it expresses a more polite form of the question.)
- Take a jacket with you. It will be colder later.