You use would when you are saying what someone believed, hoped, or expected to happen or be the case.

You use would when saying what someone intended to do.

You use would when you are referring to the result or effect of a possible situation.

You use would, or would have with a past participle, to indicate that you are assuming or guessing that something is true, because you have good reasons for thinking it.

You use would in the main clause of some 'if' and 'unless' sentences to indicate something you consider to be fairly unlikely to happen.

You use would to say that someone was willing to do something. You use would not to indicate that they refused to do something.

You use would not to indicate that something did not happen, often in spite of a lot of effort.

You use would, especially with 'like', 'love', and 'wish', when saying that someone wants to do or have a particular thing or wants a particular thing to happen.

You use would with 'if' clauses in questions when you are asking for permission to do something.

You use would, usually in questions with 'like', when you are making a polite offer or invitation.

You use would, usually in questions, when you are politely asking someone to do something.

You say that someone would do something when it is typical of them and you are critical of it. You emphasize the word would when you use it in this way.

You use would, or sometimes would have with a past participle, when you are expressing your opinion about something or seeing if people agree with you, especially when you are uncertain about what you are saying.

You use I would when you are giving someone advice in an informal way.

You use you would in negative sentences with verbs such as 'guess' and 'know' when you want to say that something is not obvious, especially something surprising.

You use would to talk about something which happened regularly in the past but which no longer happens.

You use would have with a past participle when you are saying what was likely to have happened by a particular time.

You use would have with a past participle when you are referring to the result or effect of a possible event in the past.

If you say that someone would have liked or preferred something, you mean that they wanted to do it or have it but were unable to.

You use would, usually in negative sentences, to criticize something that someone has done and to express your disapproval of it.

If you say 'would that' something were the case, you are saying that you wish it were the case.