Good TTT may have beneficial qualities, however. If teachers know how to talk to students - if they know how to rough-tune their language to the students’ level, as we have discussed above — then the students get a chance to hear language which is certainly above their own productive level, but which they can more or less understand. Such comprehensible input’ (a term coined by the American methodologist Stephen Krashen) - where students receive rough-tuned input in a relaxed and unthreatening way - is an important feature in language acquisition. TTT works!