warns
Examples
Conscience is the inner voice that warns us that someone might be looking.
History warns us that it is the customary fate of new truths to begin as heresies and to end as superstitions.
The proverb warns that 'You should not bite the hand that feeds you.' But maybe you should, if it prevents you from feeding yourself.
Who threatens, warns.
An overturned cart ahead warns the one behind.
A friend is one who warns you.