I'm not talking about behaviourist habit forming here, that notion that language could be acquired by an elaborate process of stimulus and response, but about we as teachers use habits to further student learning.
This occurred to me after reading Tom Sherrington's headguruteacher blog about flipped classrooms. He described how his physics classes got into the routine of previewing material before lessons so that classes would be more focused on discussion, question and answer that just transmission of knowledge. Some (including me) are sceptical about the flipped classroom concept, but once the routine is established, it can surely work.
Routines are useful to us. First there are the daily classroom routines we use to start and end lessons, to move from one activity to another, to set and collect homework, to police pair and group work and so on. It's hard to imagine an effective MFL teacher who does not use these.
Then the are the routines we employ as part of our methodology. My AS French classes became used to being introduced to a topic via lists of oral questions with attached vocabulary. They knew I would introduce the topic with an oral synonyms or definitions exercise, followed by some whole group question-answer to get them going and provide good model answers, followed by paired question-answer which the students would expect to lead to a write-up for homework. The expectation was that short answers would not do and students routinely produced short paragraph answers, developing their range and accuracy, whilst producing their own model answers to be referred to at oral exam revision time.
A predictable routine to teaching texts gives confidence to students. Reading aloud by teacher, some group repetition, student reading out loud, find the French, short term memory oral gap fill, correcting false sentences, then full blown question-answer - all this forms a useful routine which students get comfortable with and which, therefore, promotes learning.
A routine approach to flashcard use or picture sequences helps pupils stay with you and understand why you are doing each task in that way. Even better if you share this "secret information" with your class.
The point is that habits help students understand what is going on. When working in the target language clarity is vital, because all too often we over-estimate how much pupils understand. It is vital we lose students as little as possible.
You can go too far with habits, though. If you use the same routine too often the class will get bored, so you have to judge just how far you should rely on students responding to habit. So, let's say that with pairwork you normally let students work with their regular partner next to them. They are comfortable with this and produce good language. Why not just occasionally mix things up to give a different twist to the lesson?
So, in sum, we should not shy away from routines and indeed should develop effective ones, whilst not becoming a slave to them.