【英语】2019届二轮复习语法专题构词法（17页word版）

【英语】2019届二轮复习语法专题构词法（17页word版）

‎2019届二轮复习语法专题构词法 ‎【考点解读】‎ 英语词性是可以相互转化的。词性的转换有两种方法：转化法和缀合法（派生法）。‎ 一、转化法 转化法是由一个词类转化为另一个词类的方法，即某一个词早期迁移定型为某一个词义和词类，后来通过词义扩大或比喻等方法把它活用为其它词义和词类的方法，一般在转化义和原义之间有明显的联系。转化法一般多用于简单音节的词汇中。转化法主要分为如下四种类型：‎ ‎1. 动词转化为名词。多用来表示一次性动作，或与动作相关的事物。‎ ①We stopped there for a swim.我们在那儿停下来游了一会儿泳。swim原为动词“游泳”。‎ ②Xiao Liu's answers is perfectly right.小刘的回答是完全正确的。answer原为动词“回答”。‎ ‎2. 名词转化为动词。这类词多与名词所具有的特殊动作有关，也是修辞。例如：‎ ①He wolfed down three bowls of rice.他狼吞虎咽地吃了三大碗饭。wolf.原为名词“狼”。‎ ②He insisted on staying up to nurse the child.他坚持不睡觉来护理这个女孩。nurse.原为名词“护士”。‎ ‎3. 形容词转化为动词。‎ ‎　　①He had blacked his face with soot.他已经用煤灰把脸抹黑了。black 原为形容词“黑色的”。‎ ②My father is emptying a box of rubbish into a ‎ rubbish-cart.我爸爸正将垃圾倒入垃圾车。empty原为形容词“空的”。‎ ‎　　4. 形容词转化为名词。即用性质来指代这种性质的事物。例如：‎ ‎　　①My mother likes red.我妈妈喜欢红色（的）。red原为形容词“红色的”。‎ ‎　　②The Chinese are working-hard and brave people.中国人勤劳而勇敢。 Chinese 原为形容词 “中国的”。‎ ‎　　‎ ‎　　词性的分类中，各非独立词类所具有的双词性实际上也是转化法的一种体现。比如：介词同具名词性和动词性，是它由动词性转化成了名词性；副词同具动词性和形容词性，是它由形容词性转化成了动词性；代词同具名词性和形容词性，是它由形容词性转化成了名词性；连词同具动词性和名词性，是它由名词（更准确说是代词）性转化成了动词性。‎ 二、缀合法（派生法）‎ 缀合法（派生法）中也伴随有词性的转化，当给一个词加上后缀时常常可以改变一个词的词性。从本质上看，缀合法是合成法的简化形式，其特点主要在构成词表义的变化，而词性的变化是次要的，但因为词缀的特殊性——不能独立存在以及具有一定的词性，所以又常常把它看作是转化词性的手段。当然，这种看法是不完全正确的，我们在学习缀合法时同时学习词义和词性的双重变化，有时学习词义的变化比学习词性的变化更重要，这是我们学好缀合法的根本所在。‎ 缀合法中词性的转化主要有以下四种形式：‎ ‎（一）名词后缀 ‎1．动词 ＋ ion/tion /sion→名词(表示动作或动作过程)‎ correct v．改正；纠正　　 correction n．改正 celebrate v．庆祝 celebration n．庆祝；庆祝会 conclude v．完成；结束 conclusion n．结论；结束 ‎2．动词 ＋er/or→名词(表示从事某种职业或进行某种活动的人)‎ drive v．驾驶开车；驱赶　　　 driver n．司机；驾驶员 gather v．聚集；采集 gatherer n．收集者；采集者 conduct v．指挥；管理 conductor n．指挥；售票员 ‎3．动词＋ment→名词 punish v．惩罚 punishment n．惩罚 ‎4．动词/形容词＋th→名词 warm adj.温暖的 warmth n．温暖 ‎ grow v．生长 growth n．生长 ‎5．形容词＋y→名词 difficult adj.困难的 difficulty n．困难 ‎ honest adj.诚实的 honesty n．诚实 ‎6．形容词＋ness→名词 kind adj.善良的 kindness n．善良 ‎7．动词 ＋ance→名词 annoy vt.使烦恼 annoyance n．生气；烦恼 ‎8．ship结尾的名词(表示身份；关系；资格) ‎ member n．成员；会员 membership n．会员资格 professor n．教授 professorship n．教授身份 ‎9．ing结尾的名词 garden n．花园 gardening n．园艺 greet v．打招呼；问候 greetings n．问候 ‎（二）形容词后缀 ‎1．常见形容词后缀 ‎(1)名词＋al→形容词(表示 “有……属性”， “与……有关”)‎ agriculture n．农业　　　 agricultural adj.农业的 ‎(2)动词＋ive→形容词 decide v．决定；下决心 decisive adj.决定性的；关键的 ‎(3)动词＋able→形容词(表示“能够”，“适于”，“值得”)‎ change v．变化；兑换 changeable adj.易变的；变化无常的 ‎(4)名词 ＋ful→形容词 care n．小心；关心 careful adj.小心的；仔细的 ‎(5)名词＋less→形容词(意思与原名词相反)‎ care n. 小心；关心 careless adj.粗心的 ‎(6)名词＋ly→形容词 friend n．朋友 friendly adj.友好的 ‎(7)名词＋y→形容词 dirt n．污物；脏物 dirty adj.脏的 ‎(8)名词＋ous→形容词 ‎ danger n．危险 dangerous adj.危险的 ‎2．复合形容词的构成 ‎(1)形容词＋ing分词　 easygoing 随和的 ‎(2)形容词＋名词＋ed　 kindhearted 善良的；好心的 ‎(3)名词＋ed分词　 watercovered 被水覆盖的 ‎(4)副词＋ed分词　 wellwritten 写得好的 ‎(5)数词＋名词＋ed　 threelegged 三条腿的 ‎（三）动词词缀 ‎1．前缀en＋形容词→动词 enrich v．丰富　 enlarge v．变大；增大；扩大 ‎2．形容词＋en→动词 shorten v．缩短　 widen v．加宽 ‎3．fy结尾的动词 simplify v．简化　 classify v．归类 ‎4．ize结尾的动词 realize v．认识到　 popularize v．普及 ‎（四）否定词缀 ‎1．表示否定意义的前缀 un 不，非　unable不能够　unlucky 不幸的 dis 不，非　dishonest不诚实的　discontinuous 不连贯的 in 不，非　inactive不活跃的　incorrect 不正确的 im 不，非　impatient不耐烦的　impossible不可能的 ir 不，非　irregular 不规则的　irresponsible不负责任的 il 不，非　illogical 不合逻辑的　illegal 非法的 non 不，非　nonexistent不存在的　nonstop 直达的；连续不断的 mis 错误　mislead 误导　misunderstand 误解 dis＋动词(意义相反)　dislike不喜欢　disagree 不同意 un＋动词(意义相反)　uncover 揭开　undress 脱衣服 ‎2．表示否定意义的后缀 名词＋less→否定意义的形容词 use n. 用处；用途　　　useless adj.无用的 hope n. 希望 hopeless adj.没有希望的；绝望的 home n．家 homeless adj.无家可归的 ‎【点睛】正确使用派生词 ‎1．动词、介词、冠词、物主代词等词类后一般接名词或动名词。如果所给单词是其他词类， 就要将其改为名词， 并注意名词数的变化。‎ ‎(1) Do you know the depth (deep) of the river?‎ ‎(2) His carelessness (careful) resulted in the terrible accident.‎ ‎(3) He is one of the scientists (science) who support this theory.‎ ‎2．动词、介词后一般接名词或动名词。所给单词为动词，就要看该动词是否有名词形式。如果有名词形式，就用其名词形式。如果该动词没有名词形式，就用其动名词形式。此外，如果所给动词有名词形式，就要看其后有无宾语。如果后有宾语，用动名词形式；后无宾语，则用名词形式。‎ ‎(1) Please pay attention (attend) to your handwriting.‎ 动词attend本身有名词形式attention, 所以不用动名词attending。‎ ‎(2) His arrival (arrive) made the situation worse.‎ 动词arrive本身有名词形式arrival, 所以不用动名词arriving。‎ ‎(3) The teacher was angry at my coming (come) late.‎ 动词come没有名词，所以用动名词coming。‎ ‎(4)Thank you for your help (help)．‎ Thank you for helping (help) me.‎ ‎(5)I was happy because of his appreciation (appreciate)．‎ I was happy because of his appreciating (appreciate) my speech.‎ 上面两组句子中，helping与appreciating后都带有宾语，故用动名词。help与appreciation后没有宾语，故用名词形式。‎ ‎3．动词前后、形容词前后可有副词。如果所需词为副词时， 还要考虑副词级的变化。‎ ‎(1) The boy ran quickly (quick) to school.‎ ‎(2)“What’s that？” Father shouted angrily (angry)．‎ ‎(3) The little girl is extremely (extreme) eager to know the result of the exam.‎ ‎(4) Your composition is badly (bad) organized. Please do your writing exercise more attentively (attend) next time.‎ ‎(5) You’re driving too fast. Can you drive a bit more slowly (slow)?‎ ‎4．名词前面一般可有形容词修饰语。如果所需词为形容词时， 还要考虑形容词级的变化。‎ ‎(1) What’s the widest (width) river in the world?‎ ‎(2) The stronger (strength) we become, the more modest we should be.‎ 英语中很多单词是通过由两个或三个词合成的方式构成的，它们叫做合成词，常见合成词有合成名词、合成动词、合成形容词等几种类型。‎ ‎1. 合成名词 ⑴合成名词数量最多，其中大多数由名词+名词构成：‎ air conditioner 空调机 air raid 空袭 alarm clock 闹钟 arms race 军备竞赛 assembly line 装配线 baby-sitter 看孩子的人 ⑵也有不少合成名词由形容词+名词组成：‎ central bank 中央银行 civil rights 公民权力 first-aid 急救 current affairs 时事 dry cleaning 干洗 fast food 快餐 ⑶有些合成词由动词的-ing形式和另一词构成，如：‎ a. dining room 餐厅 drawing pin 图钉 ‎ driving license 驾驶执照 parking meter 停车计时器 b. air-conditioning 空调 central heating 集中供暖 ‎ data processing 数据处理 family planning 计划生育 ⑷还有些合成名词以其他方式或三个词构成：‎ by-product 副产品 comrade-in-arms 战友 cover-up 掩盖事实 fork-lift truck 叉车 looker-on 旁观者 open-parent-family 单亲家庭 ‎2. 合成形容词。‎ ⑴合成形容词很多由过去分词或带-ed词尾的词构成，如：‎ absent-minded 心不在焉的 air-conditioned 有空调的 bow-legged 弓形腿的 breast-fed 吃人奶长大的 broken-hearted 心碎的 clean-shaved 胡子刮得很干净 ⑵也有不少合成形容词由动词的-ing形式和另一词构成：‎ close-fitting 紧身的 easy-going 好说话的 far-reaching 深远的（影响） good-looking 漂亮的 hard-wearing 耐磨的 hard-working 勤劳的 ⑶还有一些合成形容词由“形容词+名词”（a）或“名词等+形容词”（b）构成：‎ a. deep-sea 深海的 first-class 头等的 ‎ front-page 头版的 full-length 全身大小的 ‎ last-minute 最后一分钟的 late-night 深夜的 ‎ b. all-mighty 万能的 brand-new 全新的 ‎ bullet-proof 防弹的 duty-free 免税的 ‎ ice-cold 冰冷的 interest-free 免利息的 ⑷还有一些其他形式的合成形容词，特别是一些包含副词的合成词：‎ a. 动词+副词：‎ broken-down 破旧不堪的 built-in 嵌在墙内的（橱柜）‎ built-up 盖满房子的（地区） drive-in 开车进去的（电影院） ‎ laid-back 冷静放松 see-through 透明的 b. 副词+名词：‎ off-budget 预算外的 off-campus 校园外的 off-guard 失去警惕的 off-hand 不经准备的 out-door 户外的 up-hill 上山的 c. 其他形式的：‎ all-out 全力以赴的 all-round 全面的 ever-victorious 常胜的 face-to-face 面对面的 out-and-out 彻头彻尾的 ten-minute 十分钟的 ‎3. 合成动词 ⑴ 名词+动词：‎ baby-sit 看孩子 ghost-write 为别人代写 ‎ proof-read 校队 sleep-walk 梦游 ‎ spoon-feed 用勺喂，灌输 water-ski 滑水 ⑵副词+动词：‎ overcharge 超额收费 overeat 吃得太多 undergo 经历 underwrite承担，同意保证 uphold 维护 uplift 提起，振奋 ⑶形容词或副词+动词：‎ back-pedal 往后退缩 backtrack 往回走 black-list 列入黑名单 cross-examine 盘问 ill-treat 虐待 short-change 少找钱 ⑷其他形式的合成动词：‎ blow-dry 吹干 court-martial 军法审判 deep-fry 炸 spin-dry 甩干 stir-fry 翻炒 title-tattle 闲聊 ‎【真题分析】‎ 一、单句填空 ‎1. (2018·新课标I卷) To avoid knee pain, you can run on soft surfaces to ________(strength)your leg muscles(肌肉),avoid hills and get good running shoes. Running is cheap, easy and it's always ________(energy).‎ ‎【答案】strengthen；energetic ‎2. (2018·新课标II卷) This switch has decreased ________(pollute) in the country's major lakes and reservoirs and made drinking water safer for people. According to the World Bank, China accounts for about 30 percent of total _______ (globe)fertilizer consumption.‎ ‎【答案】pollution；global ‎【解析】①考查词性转化。句意：这种转换减少了国家的一些主要湖泊里的污染。此处是及物动词decrease的宾语，所以用名词，故答案为pollution。②考查词性转换。句意：根据世界银行统计，中国占全球化肥消耗的30%。此处修饰名词fertilizer consumption，所以用形容词，故答案为global，全球的。‎ ‎3. (2018·新课标III卷) My name is Mireya Mayor. I'm a ________(science)who studies animals such as apes and monkeys.‎ ‎【答案】scientist ‎【解析】考查词性转换。根据句意可知作者的身份应是科学家而不是科学，故答案为scientist。‎ ‎4. (2018·新课标III卷) The obvious one is money; eating out once or twice ‎ a week may be________(afford) but doing this most days adds up.‎ ‎【答案】affordable ‎【解析】考查词性转化，be +adj,构成系表结构，所以此处用形容词，故答案为affordable。‎ ‎5. (2017·新课标I卷) However, be 69 (care) not to go to extremes．‎ ‎【答案】introduction ‎【解析】考查词性转换。由前面的定冠词the可知，其后应接名词，故填introduction。‎ ‎6. (2017·新课标II卷) The central London Railway was one of the most 70 (success) of these new lines，and was opened in 1900．‎ ‎【答案】successful ‎【解析】考查词性转换。根据语境并结合空前的the most可知，空处表达最高级意义。故填successful。‎ ‎7. (2017·新课标III卷) But Sarah, who has taken part in shows along with top models wants to prove that she has brains as well as beauty she is determined to carry on with her 66 (educate)．‎ ‎【答案】education ‎【解析】考查词性转换。形容词性物主代词her后需用educate的名词形式，故填education。‎ ‎8. (2016·新课标I卷) But for tourists like me, pandas are its top 61 (attract)．‎ ‎【答案】attraction ‎9. (2016·新课标I卷) The title will be 63 (official) given to me at a ceremony in London．‎ ‎【答案】officially ‎ ‎【解析】考查词性转换。修饰动词应该用副词，所以填officially。‎ ‎10. (2016·新课标II卷) Then, handle the most important tasks first so you’ll feel a real sense of 62 (achieve).‎ ‎【答案】achievement ‎【解析】考查词性转换。首先处理最重要的工作以便你能感到一种真实的成就感。介词后接名词，a real sense of achievement意为“一种真实的成就感”。‎ ‎11. (2016·新课标II卷) Recent studies show that we are far more productive at work if we take short breaks 67 (regular).‎ ‎【答案】regularly ‎ ‎【解析】考查词性转换。副词修饰谓语动词take，故填 regularly“有规律地”。‎ ‎12. (2016·新课标III卷) Food in small pieces could be eaten easily with twigs which 66 (gradual) turned into chopsticks．‎ ‎【答案】gradually ‎ ‎【解析】考查副词。应用副词修饰动词。‎ ‎13. (2016·新课标III卷) Some people think that the great Chinese scholar Confucius, who lived from roughly 551 to 479 B. C. , influenced the 68 (develop) of chopsticks．‎ ‎【答案】development ‎ ‎【解析】考查名词。根据空前的“the”及空后的“of”可知，此处应填名词development。‎ 二、单句改错 ‎1. (2018·新课标I卷) I felt happily that their life had improved.‎ ‎【答案】happily→happy ‎【解析】考查词性。他们的生活有了很大提高，我感到很高兴。此处形容词作表语，故将happily改成happy。‎ ‎2. (2017·新课标I卷) It was a relief and I came to a suddenly stop just in the middle on the road.‎ ‎【答案】suddenly改为sudden ‎3. (2017·新课标II卷) Beside, they often get some useful information from the Internet.‎ ‎【答案】Beside改为Besides ‎【解析】考查词性。besides在此表示 “除了……还”。‎ ‎4. (2017·新课标III卷) I enjoyed studying difference kinds of cars and planes，playing pop music，and collecting the late music albums.‎ ‎【答案】difference→different; late→latest ‎ ‎【解析】考查词性。①修饰名词kinds用形容词。②根据句意“收集最新的唱片”可知需要用最高级。‎ ‎5. (2016·新课标I卷) My uncle tells me that the key to his success is honest.‎ ‎【答案】honest→ honesty ‎ ‎【解析】考查词性。此处是指诚实是他成功的秘诀，用名词形式。 而形容词honest意思是“诚实的”，是指人的性格特点。‎ ‎6. (2016·新课标I卷) Instead, he hopes that our business will grow steady.‎ ‎【答案】stead→steadily ‎ ‎【解析】考查词性。根据句意可知此处grow是实意动词，意思是 “增长”，不是系动词，故用副词修饰。‎ ‎7. (2016·新课标III卷) I even felt my parents couldn’t understand me so I hoped I could be freely from them.‎ ‎【答案】freely→free ‎8. (2015·浙江卷) On the left-hand side of the class, I could easy see the football field.‎ ‎【答案】easy→easily ‎【解析】考查词性。修饰动词用副词。‎ ‎9. (2015·新课标II卷) How nice to see you again! Dad and I were terrible worried.‎ ‎【答案】terrible改为terribly ‎【解析】考查词性。修饰形容词worried要用副词，故 terrible改为terribly。‎ ‎10. (2015·新课标III卷) Lots of studies have shown that global warming has already become a very seriously problem.‎ ‎【答案】seriously→ serious ‎【解析】考查词性。句意：很多研究表明，地球变暖已成为一个严重的问题。修饰名词需要形容词。‎ ‎【对点测试】‎ 一、单句填空 ‎1. (2018·安徽巢湖一中) News of the incident quickly made 48 (it) way to Miss Davis.‎ ‎【答案】its ‎【解析】考查词性转换。这一事件的消息很快就被戴维斯小姐送到了。形容词性物主代词修饰名词，故答案为its。‎ ‎2. (2018·安徽六安市一中) The idea is to get outside quickly and 47 (safety).‎ ‎【答案】safely ‎【解析】考查词性转换。此处副词quickly（快地） 与副词safely（安全地）是并列的，作状语修饰谓语动词，故填safely. ‎ ‎3. (2018·安徽皖南8校) Things that we believed would last forever had 43 (actual) gone in a second before we realized it.‎ ‎【答案】actually ‎4. (2018·安徽皖南8校) So, silence becomes the best 48 (solve) to all difficulties and hardships.‎ ‎【答案】solution ‎【解析】考查词性转换。分析句子So, silence becomes the best ___7___ (solve) to all difficulties and hardships.可知，本句中的动词solve被形容词the best修饰，可知本题要填名词，故用solve的名词solution。句意：因此，为了达到目的，沉默是解决所有困难和困难的最好办法。‎ ‎5. (2018·全国名校联盟) Being late throws you out of the group, as you may miss important 46 (inform).‎ ‎【答案】information ‎【解析】考查词性转换。作miss的宾语，用名词，所以填information。‎ ‎6. (2018·重庆市九校联盟) Journalist Andrew Ross made the ____42____ (announce) at the end of an interview with Sophia.‎ ‎【答案】announcement ‎【解析】考查词性转换。此处由the限定做made的宾语用名词，指作出宣布，故填announcement.‎ ‎7. (2018·重庆市巴蜀中学) The report also suggests that vertebrate(脊椎动物)populations have continued to decline ___44___ (steady) by around two percent every year.‎ ‎【答案】steadily ‎【解析】考查词性转换。此处是副词修饰动词，答案为steadily。‎ ‎8. (2018·广东深圳市联考) She places Shaanxi paper-cuts over Western-style pencil sketches(素描) to create a typical presentation of Chinese elements (元素), which turns out to be a 44．(success) and impressive breakthrough.‎ ‎【答案】successful ‎【解析】考查词性转换。and连接并列结构，后面是形容词“印象深刻的”，故填successful。‎ ‎9. (2018·广西钦州市联考) …he wrote a 43 (pity)note on the toy’s ‎ box begging shoppers not to buy it until his mom could.‎ ‎【答案】pitiful ‎【解析】考查词性转换。此处修饰名词note用形容词，指令人可怜的纸条，故填形容词pitiful.‎ ‎10. (2018·重庆市南开中学) The bank officer said the bank would need some kind of ___42___ (secure) for such a loan．‎ ‎【答案】security 二、单句改错 ‎1. (2018·贵阳市清华中学) And I still remembered how our house was flooded terrible when I was little.‎ ‎【答案】terrible→terribly ‎【解析】考查词性。副词修饰动词，故把terrible--- terribly。‎ ‎2. (2018·贵州贵阳市一中) Usually two types of students tend to be inactive in classrooms: some are natural shy; some are not learning or haven’t prepared at all.‎ ‎【答案】natura→ naturally ‎【解析】考查词性。副词修饰形容词，故把natural改为naturally。‎ ‎3. (2018·贵州凯里市一中) The storm had destroyed twenty houses, thirteen of which were bad damaged.‎ ‎【答案】bad→badly ‎【解析】考查词性。修饰动词damaged，用副词，所以bad改为badly。‎ ‎4. (2018·贵州遵义四中) Half a year ago, unfortunately, my father was serious injured, which made our family even worse off.‎ ‎【答案】serious→ seriously ‎【解析】考查词性。修饰形容词injured，用副词，所以serious改为seriously。‎ ‎5. (2018·贵州遵义四中) Faced with all debts, in spite of my excellent ‎ perform at school, I had no choice but to leave school.‎ ‎【答案】serious→seriously ‎【解析】考查词性。修饰形容词injured，用副词，所以serious改为seriously。‎ ‎6. (2018·河北衡水中学) The traffic was terrible bad. What made it even worse was that our bus broke down on the way.‎ ‎【答案】terrible→terribly ‎【解析】考查词性。此处修饰形容词bad用副词，指非常糟糕，故terrible→terribly。‎ ‎7. (2018·广西联合考试) Among the four seasons in a year, summer is my favorite, which makes me free, excited and energy.‎ ‎【答案】energy→energetic ‎【解析】考查词性。make sb. +形容词，使某人怎么样，需要形容词表示宾语的特性特征，所以这里用形容词，energy改成energetic。‎ ‎8. (2018·重庆市一中) Not surprising, I am more than excited to know that the World Animal Protection is going to get some volunteers in China.‎ ‎【答案】surprising→surprisingly ‎【解析】考查词性。位于句首，修饰整个句子，且有逗号隔开，用副词，所以surprising 改成surprisingly。‎ ‎9. (2018·河北衡水中学) If I’m luckily enough to be chosen as chairman of the Students’ Union, I will spare no effort to live up to your expectations.‎ ‎【答案】把luckily→lucky ‎10. (2018·河北石家庄二中) Various of activities out of class, such as English Evening and English Corner, should be organized by the foreign language teacher,‎ ‎【答案】去掉of或 Various→Varieties ‎【解析】考查词性。Various（各种各样的）是形容词，可以直接修饰后边名词，所以要去掉of；或者把Various换成名词Varieties，构成Varieties of （各种各样的）修饰后边名词，故去掉of或 Various—Varieties.‎ 四、单句翻译（合成法、转化法）‎ ‎1. 他们计划带我们到他们的故乡观光。‎ ‎【答案】they plan to take us sightseeing in their hometown.‎ ‎【解析】sightseeing为合成名词。‎ ‎2. 我们都在笑那个心不在焉的教授。‎ ‎【答案】We were laughing about that absent-minded professor.‎ ‎【解析】absent-minded为合成形容词。‎ ‎3. 当老鼠面对各种食物可以自主选择时，它们也会忍不住吃得过多。‎ ‎【答案】When mice are faced with many different foods to choose from, they too cannot help but overeat.‎ ‎【解析】overeat为合成动词。‎ ‎4. 我们在那儿停下来游了一会儿泳。‎ ‎【答案】We stopped there for a swim.‎ ‎【解析】swim为动词转化为名词。‎ ‎5. 美国大约有三千一百万黑人。‎ ‎【答案】There are about thirty-one million blacks in the U.S.‎ ‎ ‎