had been warned与have warned有什么区别

主动与被动的区别。

warn

vt.
警戒[告](against, of)

预先通知, 预告

warn sb. off [away]
通知某人离开; 告诫某人避开
warn 加 of/that clause/to+不定式
had been warned一般和否定词连用，如：They have been warned not to go.
have warned就是完成时 sb warn sb of (to do/that)
如：They have warned them not to go.