posted by Wolfgang Butzkamm, Aachen University (RWTH), Germany
The bilingual sandwich technique (see Wikipedia) has a bilingual counterpart initiated by the learner. When the learner slips in a mother tongue word or asks for a foreign language equivalent, the teacher gives it to him right away and expects the pupil to use it and continue in the foreign language. This is a bit like the give-and-go pass in soccer or basketball. The player (= learner) passes the ball (= mother tongue word or phrase) to a team-mate (= teacher) who passes the ball ( = foreign language equivalent) back to the player that had the ball. Here is an example from my primary school children who I teach once a week. We were practising how to introduce ourselves and say something about ourselves. There was also a phrase about brothers and sisters:
Gustav: I have no brother, and I have one little sister.
Teacher: Say: But I have a little sister.
Gustav: Was heißt: Die ist nervig? [What does it mean: She’s unnerving?]
Teacher: Say: She gets on my nerves. Sie geht mir auf die Nerven. She gets on my nerves. Please come here and say it all: I have no brother, but I have a little sister, and she gets on my nerves.
And Gustav managed to repeat it nicely. Remember: The mother tongue is an immediate solution, not a last resort. Seemingly paradoxically, pupils will become less dependent on their first language, if the sandwich technique and the give-and-go pass are used in a systematic and well targeted way.
Foreign Language Education in the 21st Century 
I love the way I feel validated in my teaching techniques when I read your posts. If oral communication is a primary goal of the teacher, your techniques help tremendously.
Thank you for your comment.- Oh yes, the ear is the gateway to language, even if oral communication is not the primary goal. Let me quote from one of my books: “Simply as a muscular skill, there is probably nothing more complicated than the coordination of lips, tongue, teeth, palate, jaws, cheeks and breath to produce accurate speech sounds. We don’t remember this when, in our mother tongue, thoughts simply turn to words within us, effortlessly. In fact the biggest problem for the novice in a language taught at school is not the meanings, because they can be easily given. It’s the sounds, which can never be given, but must be conquered.”
Great post! Been reading a lot of different thoughts on teaching this subject. Thanks for the info here!