To Use Or Not To Use?

ESOL practitioners will know that use of a first language in class is often frowned upon. It is said that it uses up valuable practice time and also upsets any fluent rhythm generated in speaking activities. But is this really the case? As far as we know there hasn’t been any definitive research in this area. It can be argued, of course, that practising with non-native speakers is akin to practising anything with the underqualified i.e. that it is better than no practice at all, yet far from ideal. Naturally, it may be easier and more convenient to ask for help in one’s L1 and to offer advice, too, but wouldn’t even that be better off being expressed in the language being practiced?