One word of advice...

Advice isn't countable, so you can't have "one advice."

It sort of means "What I"m about to tell you is so basic and obvious, I can sum it up with one word."

That word might be "don't" (as in "don't do what you're thinking about doing) or "leave!" or even "run!"

Grammar GeekAdvice isn't countable, so you can't have "one advice."

That's strange. In my language it is.
Anyway, thanks, Barbara!

One word of advice is seldom limited to one word.

You can say "Let me give you a piece of advice" but not "Let me give you an advice" and not "Thanks for the advices."

Thanks for the brief! Really useful.

Sahut ***