warned against 警告不要做某事
warned of 警告某事发生
warned to 警告去做某事
A: Is it safe to walk in the forest?
A：在森林里散步安全吗？
B: The guide warned us to stay on the path.
B：导游警告我们要留在小路上。
1) 警告，提醒
2) 劝告，诫勉
3) 预警
1. 警告，提醒
verb (past tense/past participle)
1. to tell someone about a possible danger, problem, or other unpleasant situation
Synonym: caution, alert