The use of would

1) as in "wouldn't" ?

You need to realise that "would" is the conditional/subjunctive indicator and is therefore very common. Think about the other very common verbs:

to be - is - isn't
to have - has - hasn't
to do - does - doesn't

It's just a contraction of the verb and "not", which is easier and therefore accepted, unlike other verbs:

to get - gets - does not get
to drive - drive - does not drive

2) past willingness and refusal?

e.g. He asked her if she would marry him. She replied that she would (not).

What's difficult to understand? Maybe I'm not answering your question.

I hope that helps.

KP

Thanks to your reply.I've understood part 2 but in regard of part 1; let's take the following example:

would your daughter like to play with my little girl?

now,if we consider the use of would in questions and negatives,this mean that the infinitve we use here should be without to.If this is right then the above question should be just like this:

would your daughter like playing with my little girl?

Navigator

The first example is "correct" though "playing" is quite acceptable in everyday speech.

If the question was "does your daughter..." rather than "would...", then "playing" would be more appropriate, as it implies a continuous activity rather than a simple yes/no choice (which is implied by "to play").

I've probably confused you further but, in a nutshell, don't worry too much about it...either form is quite acceptable.

KP

thanks KP

Judging from the title of this thread, I think you should seek out Bipolarbear for the answer.

He is the resident expert on these matters.

p.s. You misspelled a word in the title

which one ?..

Gus is being funny - "wood" is the word he was thinking of, being slang for erection!!!

Would
Information Internet: English Grammar

Would is a very flexible word and has many uses.

GRAMMAR Would, Could and Should

should and would:

should versus would. Just as they ignore the traditional rules governing the use of shall and will, Americans largely ignore the traditional rules governing the use of should and would. The two verbs are not always interchangeable, however. You can use either should and would in the first person to express the future from the point of view of the past, but keep in mind that should sounds more formal than would: He swore that I should (or would) pay for the remark. The same principle applies to the verb in sentences that express a future condition: If I had known that, I would (or more formally, should) have answered differently. In the second and third persons, however, you only use would: She assured us that she would (not should) return. If he had known that, he would (not should) have answered differently.

should in conditional clauses. Choosing which verb to use in conditional clauses, such as those beginning with if, can be tricky. In certain clauses, you use should for all three persons: if I (or you or he) should decide to go, if it should begin to snow. Would is not acceptable in these situations, but it does appear in other kinds of conditional clauses: He might surprise you if you would give him a chance. The best advice is to follow what sounds most natural. If you’re really not sure, try a verb form in the indicative: if it begins to snow. You can also try the subjunctive: if you were to give him a chance.

when only should is correct. To express duty or obligation, you use should as the equivalent of ought to: I (or you or he) should go.

when only would is correct. You use would (and not should) to express willingness or promise (I agreed that I would do it) and to express habitual action in the past (We would walk along the canal at night). Would also has the advantage of being a polite substitute for will in requests: Would you lend me a dollar?

Thanks Debra.I'm studying now two good books;practical English grammar by A.JThomson and A.V Martinet, and the other is practical English usage by Swan, everyday.I want to be perfect and that's what I'm gonna ( going to be) be .

You're doing really well, navigator. Keep it up!

Thanks fortune