Classes of English, French, etc., should mean and entail immersion in the vehicle language.
Teens can acquire the language, although they are like adults in learning the language.
The less we teachers use their native language the better. Even announcements could be in English, French, etc. But here be careful: you ought to be able to assure they’ve understood the announcement.
Immersion can be the only single way students can learn but also acquire the target language. So don’t be afraid they won’t understand if you use the target language. They’ll do so more and more. / Photo from: Walking-Dog www houstonpettalk com. The photo is just an illustration