You can use simple word association exercises to start building more spontaneous, meaningful responses in the class. It's a pretty complex topic so I'm not going to attempt to elucidate it in its entirety here. I've just published a book on the subject. You don't have to buy it to get enough insight to put this approach to work for you in the classroom. If you or a friend has an iPad just search for Catalyst: A Conversation Taskbook for English Language Learners at iTunes and download the free sample. The introduction is included in its entirety. Read that and you'll get a sense on how you can start using the students themselves as your primary source of classroom content. If you can't find it on iTunes, there are also links on my website [refer to the signature below] to get you there. Good luck.
http://www.speekeezy.ca/Truth or Dare for English Language Learners
[Nominee: 2012 ELTon Award for Learning Resources]