caution about

caution someone about someone or something

and caution someone against someone or something

to warn someone against someone or something. Haven't I cautioned you about that before? Hasn't someone cautioned you about Daniel?

Name	Pronounced	Usage
Parvati	PAHR-vah-tee	Hinduism, Indian, Hindi
Kristaps	-	Latvian
Patxi	-	Basque
Gautstafr	-	Ancient Scandinavian
Ilithyia	-	Greek Mythology (Latinized)
John	JAHN (English)	English, Biblical