Question

The teacher tells her students, who promise they ______ quietly for three hours, that she won't give extra assignments.
would study
studied
study
have studied
will study

Answer 1

The professor tells her students, who promise they would study would study quietly for three hours, that she won't give extra assignments.

English grammar:

There are wide ranges of different tense within the core of each main tense. They are structured by adding with "helping words" or "auxiliary words", for example as be and have, prefix the verb.

For example, "I say", "I have said", "I am saying", and "I have been saying" are all in the present tense, but have different meanings. This is called aspect.