Re: difference among "would have come", "could have come", "might have come"???
***Not a teacher***
Are you saying might has less chance than would and could as I said in the question?
Like would(70~90%)>could(50%)>might(30%)?
'Would' is definite (100%), so 'might' has less chance than 'would'.
'Could' just expresses the fact that a situation is possible, but does not really express anything about a person's desire or intention about doing it. So 'could' just expresses the ability to do something (but see below).
'Might' means there is a possibility that the person would do it, but they may choose to do something else instead - so to some degree expresses more doubt about a particular outcome. So this is not just expressing the possibility of something (as with 'could'), but means there are other factors which may cause the person not to do it.
1. she would have become a super model.(she defnitely tried to become a model regardless of her appearance)
This means there is no question. If she had failed the university exam, she would have become a supermodel definitely (100%) [at least in the opinion of the speaker - even if he or she is mistaken]
2. she could have become a super model.(she was able to become a super model probably because of her appearance)
This probably means in the speaker's opinion, she would have had the ability (looks, personality etc) to become a supermodel and it is expressing the girl's ability to become one. This is where it gets a bit complicated.....When it comes to talking about aspirations, hopes, dreams etc, using 'could' can express an element of uncertainty. In other words the speaker is saying that he or she believes that the girl has the ability to become a supermodel, but even if she was to try to become one, there is a possibility that she could fail to do so. Another example of this is "He could have been a great basketball player" - perhaps said of somebody who has had an injury that means they will not play any more. "I could have been an astronaut" etc. With these sorts of 'aspirational' sentences, 'could' is more like would, but with a little more doubt (but not as much doubt as 'might')
In spoken English, it is possible to vary the emphasis and intonation on '...she could have' to express more or less likelihood (in the speaker's opinion) - but this is quite difficult to convey in a written forum.
On the other hand, when talking about simple facts (as in your previous example "If he had not been busy, he could have come to the party"), the use of 'could' means he would have had the ability to come to the party. It does not express anything about whether he would want to or not, but just that he would have had the capability if he had not been busy. Again, though, in verbal communication, you could put the emphasis in such a way that you introduce more of a doubt than this, but you would have to try quite hard.
3.she might have become a super model.(she probably didn't have good appearance, but due to some luck like meeting a sponsor, it's possible she could become a super model, but anyway this chance is very low)
Might just introduces an stronger element of doubt. She may have been very beautiful, but not particularly keen on becoming a supermodel, or she may have been very keen, but lacked the beauty or personality to become one. We don't know. All we know is that the speaker thinks there is a chance of her becoming one, but there is also considerable doubt (for some reason).
I hope this helps, rather than confuses.
Ade
