Elaine B. answered 06/02/19
Fun and Enthusiastic ESL and English Tutor
It’s an interesting question. (Are you asking as a teacher who needs advice? Or perhaps you’re a student who is tired of grammar lessons?)
When we learn our native languages as children, we learn both vocabulary and grammar at the same time. Our brains are good at finding patterns in everything around us, Finding the patterns in language helps children learn it faster.
Like children, new ESL students begin with very simple words and simple patterns (for example, subject comes before verb). As they learn more, they can grasp more complicated patterns.
But no matter what level a student is, grammatical patterns reduce the need to memorize. If you know that the plural of most nouns is formed by adding “s”, then you don’t have to look up every noun in the dictionary to see how to write its plural. You only have to memorize the ones that don’t use s.
Beyond this, grammar is important when you use a language for complex tasks. Uncertainty, or past events, or things that will happen—it would be impossible to communicate these concepts without advanced grammar.
As as a teacher, I try to teach grammar that makes sense to students because they are ready for it. When I can, I also compare English grammar to the grammar of their native languages. Students don’t realize how much similar they can be. And if they see the similarity, learning English becomes easier. And even if English is very different from what they know, seeing the contrast can still help them make sense of how English works.
So, explaining the “why” of grammar is important when it helps students improve.