Grammarly is a good grammar checker if English isn’t your first language or if you don’t write that often. It will help you check for grammar, spelling and punctuation mistakes faster. Here’s the thing: You still need to take the time to learn the fundamentals of grammar.If English is your first language, Grammarly is a useful tool because it teaches the finer points of grammar.Share on Twitter. This grammar checker acts as another line of defense, which you can use to make sure your book, article or blog post is accurate and easy to read.t will help you check for grammar, spelling and punctuation mistakes faster. Here’s the thing: You still need to take the time to learn the fundamentals of grammar. If English is your first language, Grammarly is a useful tool because it teaches the finer points of grammar.