Few/a few

1.There were -------- people in the bus. It was nearly empty.

I think "few" is suitable choice.

Is it correct?
<<<<<<<<<<<<<<<<<<<

Yes, H, it's both correct and suitable in this situation. But 'on' is a better choice for this situation than is 'in'.

Both are fine, but they mean different things:

There were a few people (more than two)
There were few people (less than four)

I would take 'few' and 'a few' slightly differently from Casi and JTT:

1. There were few people on the bus = there were not many people on the bus.

2. There were a few people on the bus = there was a small number of people on the bus.

I would use them as follows:

3. Few people bother to recycle waste paper. This is a bad thing.

4. A

Yes, when you use "few", it's rather negative, meaning "less than was expected, or should be", whereas "a few" is rather positive "maybe not many, but it's a good thing those who were there had come!"