Not only don't High Schools teach proper grammar, but few (very few) teachers know grammar themselves. You can prove my claim by a fun test: the next time you meet a school teacher in a social setting, ask him or her to define "gerund" and to provide you with an exemplary sentence. You might also ask the teacher to take this test: it is an application exam for a school in England from 1989 for eleven year olds. (Link courtesy Lou Rockwell's blog.)
Of course, because you yourself are a product (more accurately, a victim) of this system of putative education, it is likely that you don't know what a gerund is either. However, it is your good fortune to now be in one of our admirable universities which are still faithful to the ideal and practice of high academic standards. Accordingly, you have a course instructor who here directs you to purchase The Little, Brown Handbook: an excellent Canadian reference work and self-teaching tool for English grammar. A copy is also available at the Surrey campus Library, here: as is a compact version, here.
Contrary to the impression that you were given by your school, it is a very easy matter to make significant improvement in the mastery of the fundamentals of English grammar. Simply begin at the beginning of the Little, Brown Handbook and study a section a day. A section takes about fifteen minutes, and the book can be compleated at an easy pace, review included, in a couple of months. The book is organised in a very rational way, is written in plain langauge, and combines brevity and comprehensiveness in almost artistic proportion.
The reward for those who follow this discipline is incalculable: in academic success, career progress, and in any aspect of life in which confident literacy is a boon -- which is to say, every aspect. Test this assertion for yourselves: if you start now, you might improve your mark on the (significant) essay component of our Final Exam by a good twenty per-cent.