Some of the following sentences are used with any + singular countable nouns, but some are used with any + plurals. Could anybody tell me why, please?

any + singular countable noun
1. Any fog will clear by noon.
2. You can borrow any book you like.
3. When you make a late booking, you doní know where youíre going to go, do you?
It could be any destination.
4. I do not like any child.
5. Any child could do that.

any + plural countable noun
6. You could choose any colours we wanted.
7. If you find any blackberries, keep some for me.
8. Perhaps you could correct any mistakes Iíve made.