我們一起來看以下的句子，比較A與B句，你會驚嘆介系詞的魅力與表現力。B中出現的at, behind, by, on, with等都是常見的介系詞，但這小小的介系詞真的起了「畫龍點睛」的作用。
A：I couldn't believe my ears when I heard this.
B：I couldn't believe my ears at this.
A： She left six children after she died.
B： She left six children behind her.
A： If you need help, just ring me up. My telephone number is 27215033.
B： If you need help, just ring me up at 27215033.
A： We raise a toast to congratulate him on his great success.
B： We raise a toast to his great success.
A：There are so many new words in this passage, so it is hard for me to understand.
B：With too many new words in it, this passage is beyond me.
A：He misses election because of 30 votes.
B：He missed election by 30 votes.
A： The evidence is not good for him.
B： The evidence is against him.
A： I can help you finish the project.
B： I can help you with the project.
A： I'll pay the bill.
B： It's on me.