I have serious doubts too. I am more inclined to rule out 4) completely because I cannot come up with a suitable context for it. However, in theory both verbs are in the past tense and someone just might be able to come up with a good example for 4)...I had serious doubts about whether I could use /knew, might have been able/.
Hello again"if I guessed wrong, and my daughter might have been fine"
A lot of native Englsih speakers misuse tenses in conditional sentences, in fact it's becoming so common that correct usage is always a pleasant surprise. That's probably why you're confused. The example you give from a movie is typical."if I guessed wrong, and my daughter might have been fine"
I heard this in the movie.
It was the main reason why i had those doubts today..
I know the question isn't alive still for Marseillais, but it has me intrigued. I'll try to explain:'If only I ___ a little more, I ____ to help you'
1) knew, might be able
2) had known, may be able
3) had to know, might be able
4) knew, might have been able
I'd choose the first one, is that right?
I would really appreciate your help.
Hi, TT. I agree with you - in terms of grammar theory all past tense/past tense cases in conditionals should be acceptable, even 3) However, its meaning is so bizarre that it makes you wonder if at all it can ever be used. Same as 4), I think. (where "if I knew" refers to a hypothetical situation in the present, while the result clause is strictly about the past, so how can we logically have present cause and past effect?)I think it's just very hard to think of circumstances where it might apply.
Well put, TT. My first thought was to reject "knew" for "had known" in (4). Then I considered a sentence like "if I knew more about tax law, I might have been able to avoid paying a tax penalty." In this situation, I'm saying that I knew nothing about tax law before and still know nothing. As a a result a had a problem in the past with the taxman. Just as you say, at first glance it seems wrong, but in context the tense sequence works. This is yet another reason why context is so important.4) knew, might have been able (Simple past/Past conditional)at first sight, but there is a mixed conditional with this form which relates ongoing circumstances (if I knew) to a past event (I might have been able), but it's more common with negative conditions (if I didn't know, I would not have...) I think it's this that has made people accept 4 and also explains their reluctance to do so. The form is odd with a positive condition.