Iwant to know what is the more importnt language or grammar and why?

The purpose of language is to effectively communicate a message to someone else. Without grammer, the chances of communicating what you want is next to impossible. In English, word order is imperative. Using the same words, "The dog bit the boy" is a different message than, "The boy bit the dog." Other languages use cases to determine who is doing the biting. I was a linguist for many years, and when I was learning Russian, I realized I needed a refresher course in English grammar. Without a solid knowledge of English grammar, it's very hard to learn a language like Russian.