Do I Need To Know Grammar?

This question is often asked by new or potential teachers, especially since many schools in the UK and US do not teach English grammar as a matter of course.

Describing a Language

There are a couple of points to consider here. Firstly, grammar describes the way in which a language is used and, since you are teaching that language, you should be able to describe what you are teaching.

To take a simple example, suppose a student says She go to France. You know it is wrong and you can tell your student this. But suppose your student then asks, Why is it wrong? How will you answer them?

You could say spend some time to explain, but if you use grammar you'll be able to describe accurately why the utterance is wrong and how it can be corrected.

Students Outclassing Teachers

Another point is this: Many ESL schools teach grammar to help their students learn English. Your students will often have a good practical working knowledge of grammatical terminology. They will be familiar with the parts of speech and the different verb tenses, for example.

This can be daunting if, on the first day of class, a student asks, Should I use the First Conditional or Second Conditional here?

You will feel out of your depth and it could give the impression to the students that although you can speak English, you can't teach it or explain it.

Professionalism

Ask yourself this: suppose you visited a builder to talk about a an extension to your house and the builder said We'll use those hard things to build the walls, I can never remember if they're bricks or blocks. It wouldn't inspire much confidence.

What Should You Know?

At the least you should be familiar with the basics: that is the parts of speech and the basic nomenclature of grammar. You should have a basic grammar book and have read and understood it. Above all, before each lesson you should check over what you are going to teach and make sure that if a student does as a grammatical question of you that you will be able to answer them.