MODAL VERBS —– “CAN” OR “COULD“
Can and Could are two of the most used modal verbs in English. These are auxiliary verbs ( modal auxiliary verb ).
General Structures of “Can” and “Could” in a Sentence
POSITIVE FORM (+) : Subject + CAN/COULD + Verb ( first form of the verb )
NEGATIVE FORM (-) : Subject + CAN/COULD + NOT + Verb ( first form of the verb )
QUESTION FORM (?) : CAN/COULD+ Subject + Verb ( first form of the verb )
Contraction for ” CAN NOT and COULD NOT “
- can not –> can’t
- could not –> couldn’t
Using ” CAN ” and ” COULD “
1.
Can is used to express that someone is able to do something. ( Present Ability )
Examples:
- I can speak four languages.
- She can drive a car.
Could is used to express that someone is able to do something in the past. ( Past Ability )
Examples:
- He could play football well when he was a kid.
- We could not ( couldn’t ) get a job at those times.
2.
Can is used to express that something is possible. ( Present Possibility )
Examples:
- Alcohol can cause canser.
- They can stay with us when they come.
Could is used to express that something is possible in the past. ( Past Possibility )
Examples:
- A lot of crime could be prevented.
- This new method could be an important step in success.
3.
Can is used to ask or give permission for something. ( Informal Permission )
Examples:
- Can I use your book, please? ( ask for permission )
- If you want, you can go to the park. ( give permission )
Could is also used to ask or give permission for something. “COULD” is used as a more formal and polite form of “CAN”. ( Polite Permission )
Examples:
- Could I take your book, please?
- Could I please use your computer?
4.
Can is used in a question, which is not a real question, to ask somebody to do something. We want somebody to do our request ( in an informal way, especially between friends or family ). ( Informal Request )
Examples:
- Can you make me coffee?
- Can you hand me the pen?
Could is used in a question, which is not a real question, to ask somebody to do something in a polite way. “COULD” is used as a more formal and polite form of “CAN”. ( Polite Request )
Examples:
- Could you lend me this book?
- Could you tell me where the post office is, please?
5.
Can is used in offers to help someone or to do something for someone. ( Informal Offer )
Examples:
- Can I help you?
- If they like, I can carry some bags for you.
Could is used for making a suggestion. ( Suggestion )
Examples:
- If you want,we could go out for dinner after school?
- You could always call me every day of the week if it is necessary.
6.
For ” CAN NOT “;
It is used in negative saying ( when we are sure that something is not true or something is surprising )
Example:
- It can’t be raining. The sun is shining and there are no rain clouds.
( The speaker means that s/he is sure that it isn’t raining because the sun is shining and there are no rain clouds.)
It is also used in negative saying ( when something is forbidden or not allowed )
Example:
- You can’t park the car there.
For ” COULD NOT “;
It is used in negative saying ( when something is impossible to happen or untrue)
Example:
- He couldn’t have this house. He is poor.
( The speaker means that it’s not or it might not be possible because the sun is shining and there are no rain clouds.)
7.
For ” COULD ” AS A CONDITIONAL FORM OF “CAN”;
When we are talking about past time in conditionals, we use “could” instead of “can”.
Examples:
- If you called me, I could find you some suggestion.
- I could visit many places if I had more money.
