Modal verbs are auxiliary verbs that express necessity, ability, permission, possibility, or other conditions. Here’s a breakdown of the uses of "can," "will," "could," "would," "shall," and "may":
1. Can
Ability: Indicates present capability.
She can swim very well.
Permission (informal): Used to ask for or grant permission.
Can I borrow your pen?
Possibility: Expresses general possibility.
Smoking can cause cancer.
2. Will
Future tense: Expresses certainty about future actions.
She will arrive at 5 PM.
Willingness: Shows readiness to do something.
I will help you with your homework.
Promises/Offers: Used for commitments.
I will call you tomorrow.
3. Could
Past ability: Indicates capability in the past.
He could run fast when he was young.
Polite requests: More formal than "can."
Could you please pass the salt?
Hypothetical situations: Used in conditional sentences.
If I had money, I could travel.
Possibility (weaker than "can"): Suggests something is possible but not certain.
It could rain later.
4. Would
Conditional statements: Used in hypothetical or imaginary situations.
I would travel if I had more time.
Polite requests: More formal than "will."
Would you mind closing the door?
Past habits (similar to "used to"):
When I was a child, I would play outside every day.
Preferences: Used with "rather" or "prefer."
I would rather stay home.
5. Shall
Future (formal, mostly British English): Used with "I" and "we" for suggestions or obligations.
I shall attend the meeting tomorrow.
Offers/Suggestions: Used in questions for suggestions.
Shall we go now?
Strong intention/command (old-fashioned):
You shall not pass!
6. May
Permission (formal): More polite than "can."
May I leave early today?
Possibility (more formal/likely than "might"):
She may arrive late due to traffic.
Wishes (formal):
May you have a happy life.