One of the things that I have found to work very well for promoting interpersonal communication and conversation between students is to identify 6 - 8 essential questions for each unit that you teach. If you are teaching your course using the Two Week Model, these would come into play during the second (output) week of instruction. During the first (input) week you would teach the vocabulary found in the questions so that by the time you introduce them to the class, the meaning of the questions can be determined through recognition of the vocabulary.
For example, I am currently in the middle of a unit on talking about your daily routines. During this unit, I focused on the grammatical structures of reflexive verbs. The vocabulary consisted of a variety of common reflexive verbs (bañarse, lavarse, despertarse, etc) that could be related to daily routine. Here are the essential questions that I identified for the unit:
1. ¿Prefieres bañarte o ducharte?
2. ¿Con qué frecuencia te afeitas (la cara, las piernas)?
3. ¿Cúando te lavas los dientes?
4. ¿Te peinas el pelo o te cepillas el pelo?
5. ¿Qué haces para prepararte para la escuela?
6. ¿A qué hora te despiertas durante la semana?
7. ¿A qué hora te acuestas el fin de semana?
8. ¿Te secas el pelo con una toalla o una secadora de pelo?
First Steps: After you have identified the essential questions you would like students to be able to ask / answer, introduce them first as a reading activity. Ask students to read the questions and tell what they ask. This requires only vocabulary recognition and is an easier, though still extremely important, skill to develop.
Second Step: Allow students to ask you each of the questions and listen to your responses. This is essentially a listening activity as students must hear what you say and attempt to understand it. Ask them some listening comprehension questions to be sure that they understood you correctly. Also, ask them to use some inductive reasoning skills to figure out why you are answering the way you are.
Third Step: Students interview a partner with each student asking 4 questions and responding to a different 4. As the partner responds, the student who asked the question records their answers exactly as spoken on an interview form. This way, you can collect the papers and see what you need to work on - are students answering in complete sentences? Are they changing the verb forms? Are they repeating the question words unneccesarily in their responses? Work on the weak points and then perform this activity again with the students answering and asking the other 4 questions.
Fourth Step: Review the rubric you will be using with your students so they are clear about what you will be looking for. You interview the students aloud in a practice run. Ask each question 2-3 times to 2-3 different students. Ask the other students how they would score them based on the rubric.
Fifth Step: Assess the students by calling them up and having them select 3 questions at random to respond to. I usually write all 8 questions on notecards and put them face down on a table.