Why don't you start out with easy things. Everyday things that everyone knows about and, if necessary, you try it with the help of the students' mother tongue.
Have all students help find a possible way to say how the sentence this one student wanted to express could be translated into English. It works, even with the little vocab they know. Trust me, it usually works quite well. My students are always happy to talk about more private things which concern their everyday life and not only work with texts from a book. However important the book may be.
Doing that, you can introduce a lot of new vocab. And that way you might be able to teach them a lot more words which they can actually use in their everyday life.
I hope this idea helps