You would think an English teacher would know his or her grammar, right? Unfortunately this is not always the case. Native English speakers often did not take grammar as a subject. It was included in ‘English’ classes but not as a subject unto itself. From the 1960s to almost 2000, grammar virtually disappeared from British classrooms. It has begun to reappear and I think this is at least partly in response to student demand.
In Asia particularly, students want to know ‘why’ everything is the way it is. Teachers don’t always know. I mean why can ‘ough’ be pronounced eight different ways? Is there a rule? No…not really. Sure, English has rules…and an equal number of exceptions.
Oxford University Press and the other ESL publishers now feature whole series dedicated to grammar. Personally, I view teaching grammar alone as not a good idea – particularly to younger students. In high school when students are getting ready for university and its many writing tasks, then you need it. So I can understand including it at that level. But, I’m not sure of its value at primary levels. English should be taught as a whole. If you teach Listening, Reading, Writing, Spelling, Speaking and Vocabulary-building, you will have plenty of opportunities to incorporate grammar into your lessons.
Having said that, Betty Azar’s Fundamentals of English Grammar is a very good book with a separate workbook and many exercises. But, for me, doing a lot of reading will teach you how the language works just as well as a grammar book . It won’t teach you ‘why’ but do you really need to know?