Most students find it very dispiriting if they get a piece of written work back and it is covered in red ink, underlinings and crossings-out. It is a powerful visual statement of the fact that their written English is terrible. Of course, some pieces of written work are completely full of mistakes, but even in these cases, over-correction can have a very demotivating effect. As with all types of correction, the teacher has to achieve a balance between being accurate and truthful on the one hand and treating students sensitively and sympathetically on the other.