warn

warn someone about someone or something

to advise someone about the dangers associated with someone or something. Didn't I warn you about the dangers of going there? I warned you about Alice.

warn someone against someone or something

to advise someone against someone, something, or doing something. We warned them all against going to the region at this time. I warned her against Gerald.

See also: against

warn someone away from someone or something

to advise someone to avoid someone or something. We warned her away from the danger, but she did not heed our warning. Why didn't you warn me away from Roger?

See also: away

warn someone of something

to advise someone that something bad is likely to happen. I wish you had warned us of what was going to happen. Please warn John of the heavy traffic he may run into.

warn someone off

to advise a person to stay away. We placed a guard outside the door to warn people off until the gas leak could be fixed. The guards warned off everyone in the vicinity.