Which question word should be used depends on the type of information being asked for. Here are the correct question words for the given sentences:

- What did Rita do last night?

- Which friends did you invite to the party?

- Which father went to the USA last month? (this sentence doesn't make complete sense as written)

- Did you go to Spain?

- Did you go to the store?

The following are not questions and don't require a question word:

- She watched the movie.

- Ten.

- His.

- Last summer.

- I needed to buy some sugar.