I know of the idiom around the block, but I'm having some doubts as to whether I can use it in certain ways. More specifically:
- Can I use it in a phrase like "This is not your first time around block", to indicate that the person has done this before?
- If yes, then how informal is it? I mean, can I write to a colleague about a certain task something like "Since this is not your first time around the block, you know what this task involves"? To give you some context, in our workplace we're quite friendly and not too formal with each other.