Both are important. English grammar is essential to writing/speaking the language properly; it is harder than Chinese grammar but easier than French grammar. Vocabulary is what differentiates a beginner from an advanced speaker. Chinese uses pairs of words, French uses expressions and sayings, English mainly uses synonyms(different words with the same meaning).

Everything is important. You have to learn it all. If you learn just one, you won't succeed.

Both of them are important. Grammer helps you to arrange words correctly. Vocaulary supplies your needed words.

That totally depends on how and what you think.Like me,I don't know anything about grammar,but I still can communicate with foreigners. So whatever your choice is,you should do something that is suitable for yourself. 适合自己的才是最好的

vocabulary is to understand more vocabulary words.. but grammar is to learn how to read a word.. so, both are important..