Were + subject + to

Why is it right to say:
“were both engines to fail, what would happen?”

I have never seen any sentence like that one, can you help me?

And please… what is the exact meaning of that sentence?

There are two issues here. First, verb “to be” is used instead of “to do”. Therefore, we have “were to fail” instead of “failed”. Second, this is the inversion form of conditional sentence. Therefore, this is equivalent to :

“If both engines were to fail, what would happen?”
“If both engines failed, what would happen?”

This is Conditional II, i.e. unreal (future) conditional. Two engines haven’t failed in reality, but the person wonders what would happen if they did.


This is also an inversion structure only for conditional sentences. For type one: Should it rain tomorrow, we’ll go for a walk. For type two: Were it not raining, we would go for a walk(only used for progressive tenses). For type 3: Had it not been for the rain/ Had it not rained, we could have gone for a walk.

OK, thanks!

Actually, I was not familiar with inversion structures for I and II conditionals. I was sure that in given case “were” just replaces “did” without relation to condition.
So, as I undestood from your answer, “were” is used awlays for second conditional inversions and “should” for the first conditional inversions, isn’t it?

Yes. Be to usually means be obliged to.