Conversation implies a two-way exchange of language. Therefore, reaching a conversational level implies quite a high level of comprehension of the language so that we can understand what is being said to us. That means in order to converse properly we need to prepare ourselves.
I had lunch earlier this week with a college professor who is head of the Asian language department in a large university here in Vancouver. He told me that a majority of students who enrol in Asian languages quit after the first year. I was surprised to hear that.