"There is a car on/in the street"

I am not a native speaker, but I am a pretty good English speaker and I get confused with prepositions a lot. But in my opinion, for the 1st one, either on or in can work. If we say on the street, I think the emphasis is that the car was parked outside on the street, instead of parking in a garage, for instance. That is, where the car was spotted is the key in this case. But if we say in the street, I think the emphasis is that the car has been occupying that space, and so in should be more proper. So, if the emphasis is that the car has been illegally occupying the space for a long time, in should be used. But just like anything that has developed "evolutionally", it is hard to say exactly what the consensus should be.

In the UK we would not use 'on' in any of the examples given. When talking of a specific street it is always 'in the street'.

If you are talking about streets in general, there are circumstances in which you can use 'on'. e.g 'The price on the street is high'. 'You see them on the streets of London'

Now many people reading this will refer to the song in 'My Fair Lady' , 'On the Street where you Live', and infer that I am talking rubbish. But remember that MFL was originally a Broadway production.

I doubt George Bernard Shaw said 'On the street where you live...', but if someone now tries to prove that he did, it will have been because he was Irish!

When it comes to 'road' the position is quite different. Generalised terms such as being out 'on the open road', or 'on the road to nowhere' take 'on'. When it comes to named roads the position is complex. If it is a road in town with a name such as 'Chelsea Bridge Road' you could use either 'on' or 'in'. If it is a major out of town road such as the M6, you would use 'on'. That is unless you wanted to stress the very road itself. e.g. ''on' the M6 some silly old geezer was walking 'in' the road.'

1. on
2. in
3. on
4. on
5. in

Generally, on is used for a surface and in for an enclosed space. On 2 an 5, though, you used in because the situation took place within the vicinity of the street.