Ingles

Can
Can is an auxiliary verb, a modal auxiliary verb. We use can to:
* talk about possibility and ability
* make requests
* ask for or give permission
Structure of Can
Subject + can +main verb
The main verb is always the bare infinitive (infinitive without "to").
| subject | auxiliary verb | main verb | |
+ | I | can | play | tennis. |
- | He | cannot | play | tennis. || | can't | | |
? | Can | you | play | tennis? |
Notice that:
* Can is invariable. There is only one form of can.
* The main verb is always the bare infinitive.
The main verb isalways the bare infinitive (infinitive without "to"). We cannot say:
I can to play tennis
Use of Can
Can: Possibility and Ability
We use can to talk about what is possible, what we are able or free todo:
* She can drive a car.
* John can speak Spanish.
* I cannot hear you. (I can't hear you.)
* Can you hear me?
Normally, we use can for the present. But it is possible touse can when we make present decisions about future ability.
A. Can you help me with my homework? (present)
B. Sorry. I'm busy today. But I can help you tomorrow. (future)
Can: Requests and Orders
Weoften use can in a question to ask somebody to do something. This is not a real question - we do not really want to know if the person is able to do something, we want them to do it! The use of can inthis way is informal (mainly between friends and family):
* Can you make a cup of coffee, please?
* Can you put the TV on?
* Can you come here a minute.
* Can you be quiet!
Can:Permission
We sometimes use can to ask or give permission for something:
A. Can I smoke in this room?
B. You can't smoke here, but you can smoke in the garden

Could
Could is an auxiliary verb,a modal auxiliary verb. We use could to:
* talk about past possibility or ability
* make requests
Structure of Could
subject + could + main verb
The main verb is always the bare...