learn it! title
'used to'
Paul from Russia asks:

Would you answer my grammar question? In which cases should we use simple past and in which cases used to do?
Roger replies:
In my experience, Paul, many students have difficulty with the correct usage of used to, so it may be useful to spend a little time looking at this.
It refers to past habits and states. If we say that somebody used to do something, we mean that some time ago he was in the habit of doing this, but he no longer does it now. Here are some examples:
  • 'I used to smoke 30 cigarettes a day, but I gave up when I became convinced that smoking causes cancer.'
  • 'I didn't use to like cricket, but now I'm getting interested in it.'
  • 'Didn't he use to be vegetarian?' 'Yes, he did, but he started eating meat last winter and now he's a real carnivore.'
Past simple, on the other hand, describes something which happened at a definite point in time in the past. Thus:
  • 'I bought one of Lady Di's dresses at an auction in Boston.'
  • 'When did you meet your husband?' 'I met him in 1992, but we didn't get married until quite recently.'