If you are well, you are healthy and not ill.

You say well to indicate that you are about to say something.

You say well just before or after you pause, especially to give yourself time to think about what you are going to say.

You say well when you are correcting something that you have just said.

You say well to express your doubt about something that someone has said.

If you do something well, you do it to a high standard or to a great extent.

If you do something well, you do it thoroughly and completely.

If you speak or think well of someone, you say or think favourable things about them.

You use well to ask or talk about the extent or standard of something.

You use well in front of a prepositional phrase to emphasize it. For example, if you say that one thing happened well before another, you mean that it happened a long time before it.

You use well before certain adjectives to emphasize them.

You use well after adverbs such as 'perfectly', 'jolly', or 'damn' in order to emphasize an opinion or the truth of what you are saying.

You use well after verbs such as 'may' and 'could' when you are saying what you think is likely to happen.

Well is used in front of past participles to indicate that something is done to a high standard or to a great extent.

You say well to indicate that you are waiting for someone to say something and often to express your irritation with them.

You use well to indicate that you are amused by something you have heard or seen, and often to introduce a comment on it.

You say oh well to indicate that you accept a situation or that someone else should accept it, even though you or they are not very happy about it, because it is not too bad and cannot be changed.

You say well to express your surprise or anger at something that someone has just said or done.

A well is a hole in the ground from which a supply of water is extracted.

A well is an oil well.

Well up means the same as well.

You use as well when mentioning something that happens in the same way as something else already mentioned, or that should be considered at the same time as that thing.

You use as well as when you want to mention another item connected with the subject you are discussing.

If you say that something that has happened is just as well, you mean that it is fortunate that it happened in the way it did.

If you say that something, usually something bad, might as well be true or may as well be true, you mean that the situation is the same or almost the same as if it were true.

If you say that you might as well do something, or that you may as well do it, you mean that you will do it although you do not have a strong desire to do it and may even feel slightly unwilling to do it.

If you say that something is well and truly finished, gone, or done, you are emphasizing that it is completely finished or gone, or thoroughly done.

If liquids well, they come to the surface and form a pool.