PREFIX
(用于以 m, p 或 b 开头的单词前,构成反义词）表示“不”，“无”，“非”
Im- is added to words that begin with 'm', 'p', or 'b' to form words with the opposite meaning.
例句
He implied that we were emotionally immature...
他暗示我们情感上还不成熟。
Don't stare at me — it's impolite!...
别盯着我看——这是不礼貌的！