If a student prepares incorrect or off-track sentences, as a supervisor, can you assist them in reconstructing the sentences or providing some advice to help them get back on track? I'm asking these questions because, in most situations, colleagues assume that you're writing the thesis on behalf of your students.
According to my supervisor (in Europe), you can proof edit the entire thesis, give comments, reconstruct sentences, and even create certain sentences to assist students in staying on track- what are your experiences?