The issue of whether or not to use the mother tongue (L1) in the English (L2) classroom is a complicated one. Somewhere along the line (probably in the late 70s or early 80s) the idea came into fashion that using the mother tongue in the language teaching classroom was a bad thing. Everything should be done in the target language, giving the learners maximum exposure to that language (in this case English). This probably coincided with a time when ELT publishers realized that it would be cheaper to mass produce text books in which all the instructions were in English, and then ship these off to every country in the world.