We all know the standard format of the Second Conditional, past simple (did) in the if-clause, “will” in the result clause.  It’s exactly the same as in Spanish.

The third conditional, with its past perfect (had done) in the if-clause, and “would have” in the result clause, is also calqued in Spanish.

The problem comes, however, when we’re thinking in Spanish.  Here, the tenses used in the if-clause are very long, “hiciera” in the 2^nd and “hubiera hecho” in the 3^rd, and this leads speakers to think that the English versions must be equally complicated.  It’s almost as if English learners couldn’t accept that “did” and “had done” were enough, so they go and complicate it, adding “will” or “would”.  For example:

*If I would know that, I wouldn’t tell you.

*If I would have seen her, I would have told her to call you.

Students say these all the time, and you need to stop!  It’s much simpler!

If I knew that, I wouldn’t tell you

If I had seen her, I would have told her to call you.

Don’t fall into the overcomplication trap; keep it simple.  The if-clause in the Second Conditional is “did”, and in the Third, “had done”, and that’s all there is to it!