- "I'll take it from here"
- "If you don't mind"
- "Don't mind if you do"
- "I'm on board"
As a non-native speaker, I found such phrases extremely useful, and they lighten up the conversation in a friendly way unless overused (e.g., "I'm on board" for the millionth time).
What are these called exactly? Is there a category? It's not idiom (I looked it up), and I can't say it's "general speech" since it's used the same way all the time in various contexts. I don't think they're jargon, either.
They've been a real help when talking to my mostly older coworkers without the crude jokes or comments I make with friends.