We can use the past simple and the past continuous to be less direct and more polite. We often do this with the verbs 'wonder', 'think' and 'hope'. In fact, the person is wondering, hoping or thinking now, but he or she uses the past tense to be less direct. There's really very little difference between the past simple and the past continuous here.

This is similar to the way that we use past modals in English to be more polite (could is more polite than can).

• I wondered if I could borrow your car?
• I was wondering if I could speak to Susie?

• I was thinking that you could bring lunch.
• I thought that maybe we could meet a bit later?

• I was hoping you could help me.
• I hoped that you might lend me some money.