I urgently need you to check these sentences. Whad do you think I should do?

1) I graduated with honours in modern languages and I know how important memory is in learning a foreign language.
2) The headmaster of the school I'm teaching at has warned me not to check and correct my students' mistakes. I usually check all their mistakes and give them a typed correction of their mistakes.
3) I then expect them to repeat the corrected sentences.
4) The students complain that they don't want to repeat the sentences to me because the repetition is mechanical and that they don't learn anything from their mistakes.
5) The unmotivated students have joined forces against me and I don't know how to persuade them to learn!

1 answer

Commas needed in places.
http://grammar.ccc.commnet.edu/grammar/commas.htm