A simple but effective technique for on the spot ‘hot’ correction.

Look at these example classroom interactions:

Student: I /laɪked/ Paris very much.
Teacher: You /laɪked/ or /laɪkt/?
Student: /laɪkt/

Student: I have never ate Chinese food.
Teacher: ate or eaten?
Student: eaten

Compare this with simple recasting by the teacher:

Student: I have never ate Chinese food.
Teacher: You’ve never eaten Chinese food
Student: No, I don’t like spicy food.

Recasting, whilst effective in some cases can be missed by the student as they may not realise that a mistake has been made. Using the 50/50 technique makes the error much more overt and importantly requires the student to repeat the correct form.

This technique is quite effective and efficient with pronunciation mistakes and simple grammatical or lexical slips. In my experience, students seem to quite like it too.

I learnt this technique from my Delta trainer at International House London and have been using it ever since.