1. be kind for sb. to do sth． 某人做某事（對人）有好處
eg.: It is kind for you to help me work out the maths problem.
你幫我算出那道數學題真是太好了。
be kind of sb． 某人好
eg.: It's very kind of you to help me.
你能幫我，真好。
我會巧辨析：
It is +kind+for sb. to do sth．與It is+kind+of sb. to do sth．的區別：
It is+kind+of sb. +to do sth．中的kind跟sb．有關，kind是用來形容
sb．的，表示某人這麼做真是太好了。It's very kind of you to visit me．把裡面的sb．和kind提出來可以發現you are kind是說得通的．
而It is +kind+for sb.+to do sth表示做某事對某人來說很kind，這裡的kind是do sth．的屬性，裡面的sb．跟kind有直接聯繫：It's kind for you to deal with the problem．不能說you are kind.
2. be known for 因為……而出名
be known for其後所接內容表示某人或物的特點、特長等。
eg.: Mr Geldof is well-known for organizing two big pop concerts on the same day.
蓋爾多夫先生因在同一天組織兩場大型的流行音樂會而出名。
我會巧辨析：be known for一般用well修飾。即：be well-known for它的比較級是：be better-known for。
be known as 作為……而著名
be known as：其後的名詞表示一個人的身份、職業等。
eg.: Liu Huan is known as a singer.
劉歡作為一個歌手而出名。
be known in 在某地很著名
be known in後面一般接表地點的名詞。
eg.: He is well-known in the town where he was born.
他在自己出生的那個鎮子上很出名。
我會巧辨析：be known as, be known for, be known to, be known in
這些都是be known與不同介詞搭配的詞組。
be known as意為「作為……而著名」，其後的名詞表示一個人的身份、職業等。
We're sure you'll be well-known as an artist．我們相信你會成為一位著名的畫家。
be known for意為「因……而著名」，其後所接內容表示某人或物的特點、特長等。
Guilin is known for her beautiful mountains and rivers．桂林因其美麗的山水而聞名。
be known to「為……所了解/知道」，其後接表示人的詞語。「（人們都）知道」，其後接動詞原形。
He is known to all in our village．村子裡的人都了解他。
be known in：意為「在某地很著名」。
eg.:All of them are well-known in our country．所有這些人在我國都很有名氣。
3. be lacking in 缺乏
eg.: He is not lacking in intelligence.
他不笨。
我會巧辨析：in search of尋找；in place of代替；for lack of因缺乏；for fear of惟恐，以免，擔心。
4. be longing for 盼望去做……
be longing for中「for」是介詞，介詞後面接動詞的時候，動詞必須要用ing形式，構成介賓結構。
eg.: The lonely child is longing for the caress of his mother.
這個孤獨的孩子渴望母親的愛撫。
5. be ready to do 準備好做……
eg.: For crying out loud! Aren't you ever going to be ready to go out?
哎呀，我的天啊！難道你不準備出去了嗎？
6. be reduced by/to 降低了……（接數字、百分數）
eg.: Today, your weight is reduced by a few kilos.
今天，你的體重減少了（損失了）數公斤。