《英语》（八年级上册）
Unit 4 DIY
Study skills
I. Teaching aims and learning objectives
By the end of the lesson, students should be able to:
1. master the usage of the prefixes un-, in- and im- ;
2. use the suitable adjectives in contexts, and express positive or negative meanings by using the right prefixes.
II. Teaching contents
1. New words and phrases: certain, active, possible, tidy, tidy up
2. The prefixes un-, in- and im-
III. Focus of the lesson and predicted area of difficulty
Use the suitable adjectives in contexts.
Express positive or negative meanings by using the right prefixes un-, in- and im-.
IV. Teaching procedures
Step 1 Lead-in
Show the pictures and introduce the target words
T: Boys and girls. Let’s look at this picture. These boys like playing basketball. They are active in doing sports, but they are not active in study. Here “not active”, we can also say “inactive”.
T: Look, he is happy but he is not happy, or we can say unhappy.
T: I will finish my homework as much as possible. But it’s not possible for me to finish all of it. We can use “impossible” to replace “not possible”.
T: Millie’s mom is on business. Look her bedroom is not tidy. Can you help her make the room tidy? So we can use “untidy” to replace “not tidy”.
【设计意图】以图片自然导入新课。
Step 2 Presentation
1. Introduce the prefixes to the students
T: All these words are opposites and these are prefixes. So we can add “un-”,“im-”, “in-”
before an adjective to express the opposite meaning.
2. Show the rules and offer more examples
T: For most of the adjectives, we add “un-” to make it opposite. Let’s see.
T: These words begin with “p”. If the adjective begins with “p”, we usually add “im-” before it.
T: But some adjectives are special. You should add “ in-” before them to make the opposite meaning.
【设计意图】通过设计带有前缀的题目，引导学生去观察、思考、感悟和猜测其词义，并且让他们找出构词的规律来，激起学生学习的兴趣。引导学生自我探究、举一反三、触类旁通，发现列举形容词的共同点，并发现更多类似的词，启发引导学生回忆含有此类构词法的词汇
Step 3 Practice
1. Fill in the blanks
T: Can you remember the words and rules? OK! Let’s check your memory. I think all of you can do a good job. We can add “ir” or “dis” before an adjective to express the opposite meaning.
2. Correct the words in the conversation
Read the conversation below. Add the correct prefixes to some of the adjectives so that all the sentences make sense.
T: Boys and girls, here are some conversations. Can you add the correct prefixes to the adjectives so that all the sentences make sense?
3. Complete the sentences
Discuss with your partners about how to behave properly in class or school, and then finish the sentences.
4. Complete the passage
T: Here is a story of the twins, but some of the words are missing. Please read the story and then
complete it. Don’t forget to use the words with prefixes.
【设计意图】了解基本规律后，迅速对所学的前缀做巩固练习，这样能更深刻的记忆所学的词的前缀。给学生不同类型的练习来巩固所学知识。遵循任务梯度性原则，设计任务做到由易到难，由浅入深，让所有学生都能理解和掌握构词法，最终学生根据上下文，完成语篇练习。
Step 4 Activity
Play a game: a magic box
T: Here is a magic box with nine cards, and under each card there is a task for you to finish. Choose any of them and finish the task. After you finish all the tasks, there is a big surprise for you! Believe yourself. Just have a try!
【设计意图】设计时以学生已有的知识经验和学习能力为基础，通过小组合作学习，使得学生的口语表达和交际能力也有不同程度的改善或提高。
Step 5 Conclusion
Sum up the rules
For most of the adjectives, we add “un-” to make it opposite. (unkind, unhappy, unlucky …)
If the adjective begins with “p”, we usually add “im-” before it. (impossible, impolite …)
But some adjectives are special. You should add “in-” before them to make the opposite meaning. (incorrect, inactive …)
V. Homework
1. Remember all the negative prefixes.
2. Try to find out some other negative prefixes.
3. Preview the TASK part.
课件26张PPT。Unit 4 Do it yourself
Study skillsThe boys like playing basketball.
They are active in doing sports.
But they are _________ in study.
not activeinactivehappyunhappynot happyI will finish my homework as much as possible, but it’s ____________ for me to finish all of it.
impossible not possibleMillie’s mom is on business (出差). Her bedroom is ________. Can you help her make the room tidy?
untidy not tidyuntidypossible impossiblehappy unhappyactive inactiveOpposites (反义词)tidy prefixes前缀We can add _____________________ before an adjective to express the opposite (相反的) meaning.“un-”, “im-”, “in-”For most of the adjectives, we add “un-” to make it opposite.
friendly ?
happy ?
comfortable ?
certain ?
tidy ?
able ?
fair ?
lucky ?
usual ?
unfriendly
unhappy
uncomfortable
uncertain
untidy
unable
unfair
unlucky
unusualRules If the adjective begins with “p”, we usually add “im-” before it.
polite ?
possible ?
patient ?
possible ?impolite
impossible
impatient
impossible
RulesBut: pleasant ? unpleasant
expensive ?
correct ?
active ?
direct ?inexpensive
incorrect
inactive
indirectRules But some adjectives are special. You should add “in-” before them to make the opposite meaning.1.____friendly 2.____happy
3.____correct 4.____polite
5.____comfortable 6.____expensive ____healthy 8.____possible
9.____tidy 10.____certain
11.____patient 12.____able
13. 7.Check your memory!unununununununimimiminin___regular 14.___honestirdis
We can add before an adjective to express the opposite meaning.“ir-” or “dis-”
1. Annie: Do you spend a lot of time doing outdoor
sports?
Simon: Sure. It’s usual for me to stay at home all day.
2. Sandy: Our neighbour next door is putting something
on the wall.
Mum: It’s possible to sleep with all that noise.unusualimpossible Read the conversation. Add the correct prefixes
to the adjectives so that all the sentences make sense.
3. Millie: Are you able to fix your bicycle, Andy?
Andy: No. I’m certain that I can fix it myself.
4. Mum: Suzy, your room is really tidy—things
are all over the floor.
Suzy: Sorry, Mum. I’ll tidy up right now.uncertainuntidy DiscussionHow should we behave in class or in school?We should be _____________ to others.
We should be _________________ to the classmates in need.
We should not be _________ in sports.
We had better not make our classroom ___________.
We had better not wear ______________________ clothes at school.
friendly/kindpatient/helpfulinactiveuntidyuntidy/uncomfortable Tommy and Leo are twin brothers. They look so much alike that people are ______ to tell them at first sight.
If one knows them well, it’s easy to tell them apart.
Tommy likes smiling. He is patient and willing to help others. However, Leo looks ________, for he ______ smiling and never greets others. When his classmates ask him questions, he is _______ and _______ to answer them. It is ______________________ for Leo to behave that way. Leo looks ___________________
because no one wants to make friends with him. He thinks it is _____ for his classmates to treat him so coldly.
If Leo stops doing those _______ things, people will
find it _______ to differentiate Leo and Tommy unfriendlyunhappy/uncomfortable improper/impolite/incorrectunfair dislikesimpatientunwillingunableimproperimpossibleFill in the blanks with adjectives with prefixes un-,in-, im- and dis-.132456789 Playing a game: a magic box
Here is a magic box with nine cards, and under each card there is a task for you to finish. Choose any of them and finish the task. After you finish all the tasks, there is a big surprise for you! It’s ___________ (舒服的) to sit in it.It’s ________________
(不舒服的) to sit on it.comfortableuncomfortableThe boy is not very strong, for he is always ___ in sports.
A. inactive B. activeAnot direct _______
not kind _______
not possible _______
indirectunkindimpossibleunusual The snow is so heavy. It is _________ to
see such heavy snow. That is, the snow is
much heavier than usual. This isn’t an important thing. = This is an ________ thing. unimportant It is imcorrect to read someone else’s
letter.
2. David often says bad words to others,
so he is inwelcome.
3. It’s infriendly to throw stones at
birds.
incorrectunwelcomeunfriendly Correct the mistakes:Can you remember the rules?We can add __________________
_______ (before/after) an adjective to
express the opposite meaning. “un-”, “in-”, “ im-” before Work out the rule!1.________ 是最常用的否定前缀。
2.否定前缀________常用在以字母c开头的单词前，
3.否定前缀________常用在以字母p 开头的单词前。 “un-” “in-” “im-”从来都不会用在以字母l、r开头的单词前。 、b、mSummary 1. For most of the adjectives, we add “un-” to
make it opposite.
unkind, unhappy, unlucky …
2. If the adjective begins with “p”, we usually add
“im-” before it.
impossible, impolite …
3. Some adjectives are special. You should add
“ in-” before them to make the opposite
meaning.
incorrect, inactive … 1. Remember all the negative
prefixes.
2. Try to find out some other
negative prefixes.
3. Preview Task.
Homework See you next time!
Thank you!
