"What would you want to find out about a group of learners that you had to teach so that you could plan your lessons?"
This is a sentence from a pre-course task for students of CELTA course.
It is clear that the sentence is hypothetical, but is it possible to use 'would have to teach' as an alternative to 'had to teach'?
What if 'had to teach' is interpreted as a real past tense? Then the sentence becomes partly hypothetical.