B1
to make someone realize a possible danger or problem, especially one in the future
Dictionary examples:
The teacher warned us about the test, but we were too busy making memes! (0.0)
The lifeguard warned us not to run by the pool, so we skipped instead! (0.0)
My friend warned me about dating her brother, but his smile was too cute! (0.0)
We were warned not to eat the fish. (16.4)
This particular curry is extremely hot - be warned! (25.7)
Have you warned them (that) there will be an extra person for dinner? (26.0)
Put that ball down and come over here, Laura - I'm warning you! (30.5)
I was warned against/off going to the east coast because it was so full of tourists. (33.0)