keep someone posted 隨時通知某人發生甚麼事
說明：
posted 是 passive participle，當形容詞用，因此 keep 有 ve 的特性。請參考 come true 的說明。
另外也可以寫成 keep someone informed。兩句意思一樣。
例子：
I will keep you posted if my job is done.
I will keep you informed if my job is done.
by Thomas Shum