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课件网) Word power Unit 4 Hands-on fun Learning aims 能掌握否定前缀un-, in-, im-的意义及构词规则 能正确使用含否定前缀un-, in-, im-的词 Lead in What’s it about It talks about prefixes, which means “not”. Activity 1 Know the meanings of words with un-, in-, im- Look and say. lucky unlucky correct incorrect possible impossible usual unusual complete incomplete polite impolite 否定前缀: un-; in-; im- One of the most common prefixes for adjectives is un-. It means “not”. We add it to some adjectives to give them the opposite meaning. We can also use some other prefixes, such as in- and im-, to form new adjectives with the opposite meaning. 1 否定前缀un- un- 加在形容词前，让词义变成“不……的”。 happy →unhappy（不开心的）； fair → unfair（不公平的）； usual → unusual（不寻常的）。 探究 构词法 否定前缀un -, in - 和im - 2 否定前缀in- in- 加在形容词前，也表示“不……的”。correct →incorrect（不正确的）； complete → incomplete（不完整的）； visible → invisible（看不见的）。 3 否定前缀im- im- 常用于以“b” “m”或“p”开头的单词前。 patient → impatient（不耐烦的）； polite → impolite（不礼貌的）； possible → impossible（不可能的）。 Activity 2 Use adjectives with un-, in-, im- correctly A Add the correct prefixes to the words below so that they have the opposite meanings. You may use a dictionary to help you. 1 interesting _____ 2 sure _____ 3 able _____ 4 friendly _____ 5 active _____ 6 patient _____ 7 expensive _____ 8 perfect _____ uninteresting unsure unable unfriendly inactive impatient inexpensive imperfect B Read the conversations below. Fill in the blanks with words in the box, adding the correct prefixes to them. correct tidy usual possible patient 1 Simon: Do you spend much time doing DIY, Nora Nora: Yes, I do! It’s _____ to find me without a DIY job to do. What about you Simon: I’m not a fan of DIY because I’m too _____. Nora: Oh yes, it’s _____ to finish a DIY job if you are not patient. unusual impatient impossible correct tidy usual possible patient 2 Mum: Suzy, your room is really _____——— things are all over the floor. Suzy: Sorry, Mum. I’ll tidy up soon. It seems some of the answers in my homework are _____ . I‘m looking for my textbooks to check. untidy incorrect C Write about your and your friends’ DIY jobs, using the prefixes un- , in- and im- . My friends and I are DIY enthusiasts, though our projects are often imperfect. Sam built an unstable, uneven bookshelf from unsuitable wood. Jess painted a chair an uninspiring colour, leaving imprecise, uneven streaks and making it immobile. I was impatient while hanging a mirror, drilling an unfixable hole in the incorrect spot, leaving it inexplicably crooked. Our confidence remains unshakeable, but our skills are immeasurably bad. Summary 否定前缀un-, in- 和im- un- 加在形容词前，让词义变成“不……的” in- 加在形容词前，也表示“不……的” im- 常用于以“b” “m”或“p”开头的单词前 Exercise 用所给词的正确形式填空 ... ...
