(a) Have you ever been to London?
This is simply the norm for asking about whether a person has experienced travelling to London.
(b) Have you ever been in London?
This certainly could be used if the question were more pointed, VS though at the moment, I can't think of an instance.
A friend asked me the difference between the two. Initially I thought (a) was the correct way of saying it, but sometimes I have heard people say it as in (b)
Why is it okay to say:
Have you ever been to Harrods in London?
"to" a place "in" a city, VS.
Or whilst speaking on the phone to someone, "are you still in London?"
Why is it okay to use "...in London" in this context and not as in (b) above?
This has perplexed me greatly, can anyone help?
When we know that someone is "in" a place, it's just the norm to switch to 'in'. Again, 'to' is used to denote directional movement, 'in' is used to situate a person or thing in a place.