David Isaac has posted an interesting question (on his blog, Tomorrowville) about the use of the word 'could', which put me in mind of another strange example of the use (or abuse) of tense which really bothers me. You go into a shop, and the assistant asks: 'what were you looking for?' or maybe 'did you have anything particular in mind?'
To take this at face value, it looks as though the assistant, in using the past tense, is assuming that you came into the shop wanting a particular item, but now no longer want it. Why do we do this? 'What do you want?' would perhaps sound too peremptory, but 'what did you want?' is plain ridiculous. Does anyone have any asnwers?