How to encourage your students to speak out

The aim of this is to narrow the communicative approach into some practical steps towards successful speaking lesson. So the question is What would you suggest as amethod of encouraging a student to speak, for example, when they are rather shy even in thrir native language?

English teaching

the objectives are;
1- to rivise animals name , rabbit,cow,donkey,pig,horse,dog which already taught
2- to use adjective comparative and superlative ; big ,small ,fast
3- use the question Which is bigger the cow or the horse?
procedures:
1- ask students what is this?
2- write adjectives on the bb and make some comparsons
3-students in pairs ask each other which is faster the dog or the horse