What is the Simple Past Tense used for?

The Simple Past Tense is used (a) with finished actions, states or habits in the past when we have a finished time word (yesterday, last week, at 2 o'clock, in 2003) as in 'I went to see my aunt yesterday; and (b) to talk about things that are not real in the present or future as in 'If I won the lottery, I would buy a house', or, 'I wish I had more time!'