How are phrase structure rules useful in teaching students about the grammar of language?

Paper detalis:

The book you will need to have already is Introduction to Language 11th Edition By Victoria Fromkin, Robert Rodman, Nina Hyams. This assignment has several parts; an exercise section at the beginning and an essay. In the Essay part there are 3 choices to choose from, do:
A. How are phrase structure rules useful in teaching students about the grammar of language?
—You would also need to find 2 other references from peer-reviewed research.