What do you think is more important for ESL students to learn, vocabulary or grammar?

Providing a context where students can communicate properly is more important than both. Linguistic competence is just one element (among others). Discourse competence, sociolinguistics competence and strategic competence are three components that also help in what is so-called "communicative competence". Moreover, it is not just vocabulary or grammar that should be emphasized, but rather how to teach them.

I must say that grammar is much more important than vocabulary. Learning a second language is like building a new house. You want to have a strong foundation otherwise no matter how beautifully it is decorated the house will eventually crumble down. Vocabulary is a part of the language used and hence is enriched by constatnt use.

Neither. Students should be taught how to communicate; i.e., using and experiencing the language. Teaching grammar and vocabulary is ineffective when it is not done in context. A simple dialog can teach grammar through patterns, and also vocabulary, without having to actually "explain" things directly.

There are non-native speakers of English who are like walking dictionaries; they know more vocabulary than some native speakers, but can not put a sentence together correctly.

At the same time, studying a grammar book from beginning to end will teach you everything ABOUT the language, but not how to communicate with native speakers.

Language is far too dynamic than what is learned from grammar and vocabulary, which are both necessary elements of any language by the way.

However, to answer the question, vocab has priority because knowing some basic vocabulary in the target language (pronouns, interrogatives, demonstratives, then basic phrases) is necessary as a base to begin to work with and understand how to use grammar effectively.

To know alot of vocas

vocabulary and speaking, the rest can come later

It depends on the native language of your students, but I would start out with basic, common vocabulary, then build on that with grammar, all the while keeping the differences of English and their native tongue in mind. The discrepancies between one language and another ought to be pointed and explained, but not judged. Prejudice can't help your teaching anymore than calling a willing student an idiot.

How can we separate vocabulary and grammar from each other? They are two sides of the same coin. Grammar cannot exist without reasonable vocabulary and vocabulary is useless without the ability to use them in structures. I think language should be taught as usages, which is a combination of grammar and vocabulary. Don’t forget the fact that both these can be acquired passively if they are taught to read well!

Vocabulary

Vocabulary is important because certainlyin learninga second language is interested in the conversation and the conversation vocabulary