Drills are a feature of langauge courses similar to the Audio-Lingual Method. The student is prompted with various "keys", and must make the correct transformation of the sample sentence. The student then hears the correct response on the tape, and is prompted with a new key.
While some people find the drills very boring to do, they are none-the-less very effective at teaching and reinforcing particular grammar points.
Example (from the FSI French course, translated into English)
* Tape: "I am pleased to meet you." * Student: "I am pleased to meet you." * Tape: He is pleased * Student: "He is pleased to meet you." * Tape: My brother * Student: "My brother is pleased to meet you"
* Tape: speak French * Student: I am pleased to speak French. * Tape: have lunch with you * Student: I am pleased to have lunch with you