英語成語、短語、慣用語很多。有時，它們的構造看起來不合邏輯，甚至不合常理，但又不能隨意更改。例如，我們用雙腳步行，應該是“on feet”，但偏偏是“on foot”才對。一般上說，成語、短語或慣用語中的字眼不可用別的字取代，詞序也不可調換，因為一字之差，詞序一換，原意可能走樣，甚至毫無意思。
　　在下列各組句子中，(a)錯、(b)對：
　　1a. What is the reason of all this shunning away from blue-collar work?
　　b. What is the reason of all this shying away from blue-collar work?
　　2a. I am working on the behalf of my company.
　　b. I am working on behalf of my company.
　　3a. We need a capable person to help us in time of difficulties.
　　b. We need a capable person to help us in times of difficultes.
　　4a. In term of economic development, our country has done a good job.
　　b. In terms of economic development, our country has done a good job.
　　5a. Few would like to make friend with hypocrites.
　　b. Few would like to make friends with hypocrites.
　　6a. Let‘s discuss this matter in details.
　　b. Let‘s discuss this matter in detail.
　　7a. That rich woman is covered with jewellery from top to toes.
　　b. That rich woman is covered with jewellery from top to toe.
　　8a. For the better or worse, we must try to get along with our colleagues.
　　b. For better or worse, we must try to get along with our colleagues.
　　9a. The Public Relations Officer did not speak much. What is worst, she hated to mingle with people.
　　b. The Public Relations Officer did not speak much. What is worse, she hated to mingle with people.
　　10a. All must come to the meeting without failure.
　　b. All must come to the meeting without fail.
　　11a. Most of the students learn historical facts by hard.
　　b. Most of the students learn historical facts by heart.
　　12a. A holiday abroad will take your mind of the work tension for a while.
　　b. A holiday abroad will take your mind off the work tension for a while.
　　13a. It is out of question for you to go tonight; you haven‘t finished your assignment yet.
　　b. It is out of the question for you to go tonight; you haven‘t finished your assignment yet.
　　14a. Students should spend their time studying instead of involving in destructive activities.
　　b. Students should spend their time studying instead of involving themselves in/ getting involved in destructive activities.