Modal verbs (modals) are for example may, can, must, should, need. They express an ability, permission, wish etc. to do something. (I may, can, must swim.) Many modal verbs cannot be used in all of the English tenses. That's why we need to know the substitutes to these modal verbs.
1. can
| Use | Examples |
|---|---|
| ability to do sth. in the present (substitute form: to be able to) | I can speak English. |
| permission to do sth. in the present (substitute form: to be allowed to) | Can I go to the cinema? |
| request | Can you wait a moment, please? |
| offer | I can lend you my car till tomorrow. |
| suggestion | Can we visit Grandma at the weekend? |
| possibility | It can get very hot in Arizona. |
2. could
| Use | Examples |
|---|---|
| ability to do sth. in the past (substitute form: to be able to) | I could speak English. |
| permission to do sth. in the past (substitute form: to be allowed to) | I could go to the cinema. |
| polite question * | Could I go to the cinema, please? |
| polite request * | Could you wait a moment, please? |
| polite offer * | I could lend you my car till tomorrow. |
| polite suggestion * | Could we visit Grandma at the weekend? |
| possibility * | It could get very hot in Montana. |
3. may
| Use | Examples |
|---|---|
| possibility | It may rain today. |
| permission to do sth. in the present (substitute form: to be allowed to) | May I go to the cinema? |
| polite suggestion | May I help you? |
4. might
| Use | Examples |
|---|---|
| possibility (less possible than may) * | It might rain today. |
| hesitant offer * | Might I help you? |
5. must
| Use | Examples |
|---|---|
| force, necessity | I must go to the supermarket today. |
| possibility | You must be tired. |
| advice, recommendation | You must see the new film with Brad Pitt. |
6. must not/may not
| Use | Examples |
|---|---|
| prohibition (must is a little stronger) | You mustn't work on dad's computer. |
| You may not work on dad's computer. |
7. need not
| Use | Examples |
|---|---|
| sth. is not necessary | I needn't go to the supermarket, we're going to the restaurant tonight. |
8. ought to
simliar to should – ought to sounds a little less subjective
| Use | Examples |
|---|---|
| advice | You ought to drive carefully in bad weather. |
| obligation | You ought to switch off the light when you leave the room. |
9. shall
used instead of will in the 1st person
| Use | Examples |
|---|---|
| suggestion | Shall I carry your bag? |
10. should
| Use | Examples |
|---|---|
| advice | You should drive carefully in bad weather. |
| obligation | You should switch off the light when you leave the room. |
11. will
| Use | Examples |
|---|---|
| wish, request, demand, order (less polite than would) | Will you please shut the door? |
| prediction, assumption | I think it will rain on Friday. |
| promise | I will stop smoking. |
| spontaneous decision | Can somebody drive me to the station? - I will. |
| habits | She's strange, she'll sit for hours without talking. |
12. would
| Use | Examples |
|---|---|
| wish, request (more polite than will) | Would you shut the door, please? |
| habits in the past | Sometimes he would bring me some flowers. |
* These are no past forms, they refer to the future.