初中英语语法动词八种时态详解

初中动词八种时态详解 初中英语八种时态归纳复习 时态是英语学习中一个至关重要的内容，广大初中学生在实际运用时，往往对时态问倍感棘手，下面我们就归纳复习一下这几种时态。 一、 一般现在时 (一)定义 示经常性或习惯性的动作，或存在的状态，还表示主语具备的性格 和能力及客观真理。 例:I get up at 6:30 in the morning . She is at home . (二)构成 主要用动词原形表示，当主语是第三人称单数时，在动词词尾加s/es。 (三)句型 1、肯定句:主语+谓语+其他。 She reads English everyday . 2、否定句:主语+don’t/doesn’t+谓语+其他。 He doesn’t get up at 6:30 in the morning . 3、一般疑问句:Do/Does+主语+V原+其他, Do you like English ? Yes ,I do ./No, I don’t . 4、特殊疑问句:特殊疑问词+do/does+主语+V原+其他, What time do you get up every morning ? Where does your father work ? (四)时间状语 Always, usually, often, sometimes, every week (day, year, month…), once a week(day, year, month…), on Sundays, (五)用法 1、表示经常性或习惯性的动作，或存在的状态，带与表示频率的时间状语如:often , sometimes , usually，always , everyday year，month((() , once/twice a week (month , year , etc.) , seldom , on Sundays等连用。 I leave home for school at seven every morning . 2、表示客观真理，科学事实、格言警句。 The sun rises in the east .日出东方。 The earth goes around the sun .地球绕着太阳转。 Ten minus two is eight.十减二等于八。 Light travels faster than sound .光的速度比声音的速度快。 The United States lies by the west coast of the Pacific Ocean. 美国位于太平洋西岸。 3、根据英文语法规定，当主句的谓语动词是一般将来时，那么时间或条件状语从句的谓语动词只能用一般现在时来表示将来要发生的动作。 I'll tell him the news when he comes back. 他回来时，我将告诉他这个消息。 If you come this afternoon,we’ll have a meeting . 4、仅为了描述状态、性质、特征、能力等等。这里的目的是为了"描述现阶段的动作或状态"，其重点"不是强调动作发生的时间、或进行的状态"。例如: He can speak five foreign languages .他能说五种外语。 That is a beautiful city .那是座美丽的城市。 hydrogen oxidation sodium solution (about 5%) in the and to just is micro-alkaline, then with distilled water diluted to scale, mixed uniform. this liquid as into Hou restore sugar of stay measuring liquid. 2.2.2 titration: glucose, the same operation. 2.2.3 titration: according to 3.8.3.2.3 the same operation. 2.3 results of calculations and reducing sugar content after conversion (13): X= (ax4000) ? (Vxm) (13) in the formula: X--content of reducing sugars in the sample (in terms of invert sugar),%; A--Rhine-Ed sugar scale (see table 5) found that reducing sugar consumption coefficient of liquid invert sugar corresponding to the product to be tested. F--concentration of fehling solution; V--reducing sugar consumption be measured by the time drops by volume, mL; M--sample mass, g. parallel test results allow errors to 0.5%. Sucrose content by type (14): X= (A-B) x0.9 (14): x--of sucrose content,%; A--transformed the reducing sugar content,%; Before B--into the reducing sugar content,%. Note: in case of dispute, the arbitration law of potassium ferricyanide law. Ash hydroxymethyl furfural by 1 1.1 reagents and materials, except as otherwise provided, the reagents are pure, to distilled water. 1.1.1 barbituric acid solution: weigh 500mg barbituric acid in a beaker of plus 70mL distilled water placed on the hot tub heating mixing the solution, cooled and moved into the 100mL volumetric flask, Changjiang River is one of the longest rivers in the world. 长江是世界上最长的河流之一。 She majors in music .她主修音乐。 All my family love football .我全家人都喜欢足球。 My sister is always ready to help others . 我妹妹总是乐于助人。 (四)动词第三人称单数形式变化 1、一般情况下，动词后直接加-s; 如:help-helps ,clean-cleans ,give-gives等。 2、以s，x，ch，sh或o结尾的动词，在词尾加-es; 如:dress-dresses,fix-fixes,watch-watches,finish-finishes等。 3、以辅音字母加y结尾的动词，把y变为i，再加-es; 如:study--studies,fly-flies,carry--carries等。 4、动词have遇在主语是第三人称单数时，have改为has， 如:He has an interesting book . 5、动词be遇有主语是第一人称单数时，be改为am，遇有主语是第二人称时，be改为are，遇有主语是第三人称单数时，be改为is 二、 一般过去时 (一)结构 一般过去时用动词的过去式表示。 基本结构 否定句 一般疑问句 Be动词 was/ were+not was或were提前，放于句 首 行为动词 didn’t+do(动词原形) Did+主语+do(动词原形) 注:在一般过去时的句子中，谓语动词可分为两类一类是be动词，其形式为was与第一、三人称单数连用，were与第二人称和复数人称的主语连用。凡是由be动词做谓语的句子，变否定句时，直接在其后加not,即wasn’t 或weren’t，变一般疑问句将was/ were放在句首，句末用问号。另一类谓语动词是由行为动词来充当，如stayed\went\visited等,这一类动词做谓语时，可与任何人称连用，句子变否定时，要在主语后面，动词的前面加didn’t，动词用原形;一般疑问句是把did提到句首，动词用原形。 I was in Shanghai last year . I wasn’t in Shanghai last year . Was you in Shanghai last year ? He went to the park yesterday . He didn’t go to the park yesterday ? Did he go to the park yesterday ? (二)句式 1、肯定句:主语+动词过去式+其他。 I was in Beijing yesterday . I went to the beach yesterday . 2、否定句:主语+wasn’t 或weren’t+其他。 主语+didn’t + V原+其他。 I wasn’t in Beijing yesterday . I didn’t go to the beach yesterday . hydrogen oxidation sodium solution (about 5%) in the and to just is micro-alkaline, then with distilled water diluted to scale, mixed uniform. this liquid as into Hou restore sugar of stay measuring liquid. 2.2.2 titration: glucose, the same operation. 2.2.3 titration: according to 3.8.3.2.3 the same operation. 2.3 results of calculations and reducing sugar content after conversion (13): X= (ax4000) ? (Vxm) (13) in the formula: X--content of reducing sugars in the sample (in terms of invert sugar),%; A--Rhine-Ed sugar scale (see table 5) found that reducing sugar consumption coefficient of liquid invert sugar corresponding to the product to be tested. F--concentration of fehling solution; V--reducing sugar consumption be measured by the time drops by volume, mL; M--sample mass, g. parallel test results allow errors to 0.5%. Sucrose content by type (14): X= (A-B) x0.9 (14): x--of sucrose content,%; A--transformed the reducing sugar content,%; Before B--into the reducing sugar content,%. Note: in case of dispute, the arbitration law of potassium ferricyanide law. Ash hydroxymethyl furfural by 1 1.1 reagents and materials, except as otherwise provided, the reagents are pure, to distilled water. 1.1.1 barbituric acid solution: weigh 500mg barbituric acid in a beaker of plus 70mL distilled water placed on the hot tub heating mixing the solution, cooled and moved into the 100mL volumetric flask, 3、一般疑问句:was/ were+主语+V原+其他, Did +主语+V原+其他, Were you in Beijing yesterday ? Did you go to the beach yesterday ? 4、特殊疑问句:特殊疑问词+ was/ were+主语+其他, 特殊疑问词+did+主语+V原+其他, Where were you yesterday ? Where did yougo yesterday ? (三)时间状语 ago, yesterday, the day before yesterday, last week, last(year, night, month…), in 1989, just now, at the age of 5, one day, long long ago, once upon a time, etc. (四)用法 1、表示过去某一时刻或某一段时间里所发生的动作或情况，常与明确的时 间状语连用，如:yesterday,last week(month , year…),…ago,the other day ,just now ,at the age of…,in 1980等连用。如: At the age of ten ,she began to learn to play the piano . 2、表示过去经常发生或反复发生的动作，常与表示频度的时间状语连用。 When I was a child ,I often play the football in the street . 3、在时间、条件状语从句中，常用一般过去时态代替过去将来时。 He said he wouldn’t go if it rained . (五)动词过去式的规则变化 1) 一般情况下, 在动词原形末尾加-ed ; 如look-looked 2) 结尾是字母e 的动词加-d, 如 practice-practiced; 3) 结尾是“辅音字母+y” 的动词, 变“y”为“i” 再加ed, 如study studied; 4) 重读闭音节结尾, 双写动词尾的辅音字母，再加ed, 如stop stopped。 不规则动词表 Infinitive Past tense Infinitive Past tense catch caught come came do did draw drew drink drank drive drove eat ate fall fell am is was are were begin begun break broke bring brought build built buy bought can could 动词过去式的记忆口诀 动词一般过去时, 表示过去发生事;be用was或用were, have, has变had; 谓语动词过去式, 过去时间坐标志;一般动词加- ed, 若是特殊得硬记。 否定句很简单, 主语之后didn’t添;疑问句也不难, did放在主语前; 如果谓语之前有did, 谓语动词需还原;动词若是was, were, 否定就把not 添。 三、一般将来时 (一)概念 hydrogen oxidation sodium solution (about 5%) in the and to just is micro-alkaline, then with distilled water diluted to scale, mixed uniform. this liquid as into Hou restore sugar of stay measuring liquid. 2.2.2 titration: glucose, the same operation. 2.2.3 titration: according to 3.8.3.2.3 the same operation. 2.3 results of calculations and reducing sugar content after conversion (13): X= (ax4000) ? (Vxm) (13) in the formula: X--content of reducing sugars in the sample (in terms of invert sugar),%; A--Rhine-Ed sugar scale (see table 5) found that reducing sugar consumption coefficient of liquid invert sugar corresponding to the product to be tested. F--concentration of fehling solution; V--reducing sugar consumption be measured by the time drops by volume, mL; M--sample mass, g. parallel test results allow errors to 0.5%. Sucrose content by type (14): X= (A-B) x0.9 (14): x--of sucrose content,%; A--transformed the reducing sugar content,%; Before B--into the reducing sugar content,%. Note: in case of dispute, the arbitration law of potassium ferricyanide law. Ash hydroxymethyl furfural by 1 1.1 reagents and materials, except as otherwise provided, the reagents are pure, to distilled water. 1.1.1 barbituric acid solution: weigh 500mg barbituric acid in a beaker of plus 70mL distilled water placed on the hot tub heating mixing the solution, cooled and moved into the 100mL volumetric flask, 表示将要发生的动作或存在的状态。 There will be an English party next Saturday . We will come to see you tomorrow . (二)结构 1、由will +动词原形构成，其will适用于各种人称，与主语连在一起时，常常缩写为’ll。变否定句时，只需在will后加not，可缩写为won’t 。在疑问句中，will需提前，构成will+主语+动词原形的结构。 He will arrive here this evening .他今晚抵达这里。 2、shall+动词原形(常用于主语为第一人称) I shall / will not be free tomorrow .我明天没空。 3、be going to+动词原形(打算、准备做某事) He is going to spend his holidays in London . 他打算在伦敦度假。 (三)时间状语 Tomorrow, next day(week, month, year…),soon, in a few minutes, by…,the day after tomorrow, etc. (四)用法 1、表示在将来某个时间将要发生的动作或存在的状态，常与表示将来的时间状语，如:tomorrow, next day(week，month，year(((()， this evening (weekend …), in the future , in a few minutes， the day after tomorrow ,by(((， soon 等连用。 I will pay a visit to Shanghai next week . I hope you won’t be late next time . 2、当主句为一般现在时，在以after,when,while,as soon as ,if ,unless等引导的时间或条件句中，要用一般现在时表将来。 I’ll do it better if the teacher gives me another chance . 四、过去将来时 基本结构: 主语+was/were +going to + do+其他;主语+would/should + do+其他 用法: 表示过去的某时以后将要发生的动作。但这个"将来"时间绝不会延伸到“现在”;而仅限于“过去时间区域内”。由此可以看出，含这个时态的句子常带一个表示“过去某个时间点”的状语。这个状语或是一个短语，或是一个句子。这个时态常用于: A)宾语从句或间接引语中;B)表示过去习惯性的动作;C)表示过去情况中的“愿望”、“倾向”，多用于否定句。例如: A) When I thought about it , I wondered what their reaction would be . 当我考虑这件事时，我想知道他们的反应是什么。 She told me that she would go on trip to Europe the next day. 她告诉我，她第二天要去欧洲旅行。 He didn't expect that we would all be there. 他没料到我们会全在那儿。 B) During that period , he would do morning-exercises every day. 在那段时间，他每天早锻炼。 Whenever he had time, he would help his mother with some housework. 无论他什么时间有空,他总是帮他妈妈干点家务活。 hydrogen oxidation sodium solution (about 5%) in the and to just is micro-alkaline, then with distilled water diluted to scale, mixed uniform. this liquid as into Hou restore sugar of stay measuring liquid. 2.2.2 titration: glucose, the same operation. 2.2.3 titration: according to 3.8.3.2.3 the same operation. 2.3 results of calculations and reducing sugar content after conversion (13): X= (ax4000) ? (Vxm) (13) in the formula: X--content of reducing sugars in the sample (in terms of invert sugar),%; A--Rhine-Ed sugar scale (see table 5) found that reducing sugar consumption coefficient of liquid invert sugar corresponding to the product to be tested. F--concentration of fehling solution; V--reducing sugar consumption be measured by the time drops by volume, mL; M--sample mass, g. parallel test results allow errors to 0.5%. Sucrose content by type (14): X= (A-B) x0.9 (14): x--of sucrose content,%; A--transformed the reducing sugar content,%; Before B--into the reducing sugar content,%. Note: in case of dispute, the arbitration law of potassium ferricyanide law. Ash hydroxymethyl furfural by 1 1.1 reagents and materials, except as otherwise provided, the reagents are pure, to distilled water. 1.1.1 barbituric acid solution: weigh 500mg barbituric acid in a beaker of plus 70mL distilled water placed on the hot tub heating mixing the solution, cooled and moved into the 100mL volumetric flask, C) No matter how difficult the work was , he would keep on doing it until he accomplished it . 不管工作有多难，他总会坚持不懈地把它干完。 They knew that we would never permit such a thing. 他们知道我们绝不会允许发生这样的事。 Even after the lecture ended, the audience would not leave . 甚至在讲座结束之后，听众仍不肯离去。 过去将来时基本结构 过去将来时由would, was/were going to, was/were to was/were about to等加动词原形构成, 也可由was/were on the point of加动名词构成。 例句: I knew you would agree. 我知道你会同意的。 I said I would arrange everything. 我说我来安排一切。 时间状语: The next day (morning, year…),the following month(week…),etc. 五、现在进行时 (一)结构 由 Be(am,is,are) ，动词—ing 构成。 (二)用法 1、表示说话时刻正在进行的动作及行为，或者包括说话时刻在内的一段时间正在进行的动作。常用时间状语及标志词:now( at the moment ) , listen , look , this week , this evening , these days 等。 Listen , Someone is playing the piano in the next room . 2、表示一种渐进的过程。 My younger brother is becoming more and more insterested in English . 3、与always , all the time , forever等连用，表示说话人某种强烈的情感，如:赞许、批评;喜欢、厌恶等。例如: He is always thinking of others , not of himself . (表示赞许)他总是为他人着想，而不为自己。 She is often doing well at school. (表示满意)她在学校学习挺不错的。 Are you feeling better today? (表示亲切)你今天觉得好一些吗, One of my roommates is constantly leaving things about.(表示不满)我的一个室友老是乱扔东西。 Some sellers are often knocking at our door and promoting their products to us . (表示不喜欢) 有些推销员老是敲我家的门,向我们推销他们的产品。 4、表示移位的动词，如go,come,leave,start,arrive等，其现在进行时可表将来。 She is leaving for Beijing next weak . My friend is coming for dinner . (三)句型 1、肯定句:主语+ be(am,is,are) ，动词—ing +其他。 I am studying now . 2、否定句:主语+ be +not+动词—ing +其他。 I am not studying now . 3、一般疑问句:Be+主语+动词—ing +其他, hydrogen oxidation sodium solution (about 5%) in the and to just is micro-alkaline, then with distilled water diluted to scale, mixed uniform. this liquid as into Hou restore sugar of stay measuring liquid. 2.2.2 titration: glucose, the same operation. 2.2.3 titration: according to 3.8.3.2.3 the same operation. 2.3 results of calculations and reducing sugar content after conversion (13): X= (ax4000) ? (Vxm) (13) in the formula: X--content of reducing sugars in the sample (in terms of invert sugar),%; A--Rhine-Ed sugar scale (see table 5) found that reducing sugar consumption coefficient of liquid invert sugar corresponding to the product to be tested. F--concentration of fehling solution; V--reducing sugar consumption be measured by the time drops by volume, mL; M--sample mass, g. parallel test results allow errors to 0.5%. Sucrose content by type (14): X= (A-B) x0.9 (14): x--of sucrose content,%; A--transformed the reducing sugar content,%; Before B--into the reducing sugar content,%. Note: in case of dispute, the arbitration law of potassium ferricyanide law. Ash hydroxymethyl furfural by 1 1.1 reagents and materials, except as otherwise provided, the reagents are pure, to distilled water. 1.1.1 barbituric acid solution: weigh 500mg barbituric acid in a beaker of plus 70mL distilled water placed on the hot tub heating mixing the solution, cooled and moved into the 100mL volumetric flask, Is she studying now ? Yes ,she is ./No,she isn’t . 4、特殊疑问句:特殊疑问词+ Be+主语+动词—ing +其他, What are you doing now ? (四)时间状语 Now, at this time, days, etc. look. listen (五)动词的现在分词形式构成的几种方法: 1、一般在动词原形结尾直接加-ing 。 read-reading ，go-going ，visit-visiting 2、以不发音字母e结尾的动词，去e再加-ing。 live-living, write-writing，make-making,take-taking 3、 以重读闭音节结尾且末尾只有一个辅音字母的词，双写这个字母再加-ing 。 sit-sitting,begin-beginning,get-getting,run-running, put-putting 4、少数几个以ie结尾的动词，变ie为y再加-ing。 die-dying, lie-lying, tie-tying 六、过去进行时 (一)结构 由was/were+动词-ing构成。 (二)用法 表示过去某一时刻或某一段时间正在进行或发生的动作。动作发生的特指时间常用一个短语或时间状语从句来表明，如:at this time yesterday，at 7:00 yesterday ，last night ,from seven to nine ,at that time以when或while引导的时间状语从句等。 My family were watching TV at this time yesterday . 注意:(1)以when引导的时间状语从句中，从句动作，主句用过去进行时，表示一个动作发生时，另一个动作正在进行。 When he called me , I was having dinner . (2)以while引导的时间状语从句中，从句与主句的动作在过去某一时刻同时进行，while常译为“当……的时候，同时”。 Tom was doing his hmework while hie sister was watching TV . (三)时间状语 at this time yesterday, at that time或以when引导的谓语动词是一般过去时的时间状语等。 七、现在完成时 (一)含义 现在完成时用来表示现在之前已发生或完成的动作或状态，但其结果却和现在有联系, 也就是说, 动作或状态发生在过去但它的影响现在还存在。 e.g. I have lost my wallet. (含义是:现在我没有钱花了。) Jane has laid the table.(含义是:已可以吃饭了。) Michael has been ill.(含义是:现在仍然很虚弱。) He has returned from abroad. (含义是:现在已在此地) (二)结构 助动词have /has+动词过去分词，主语为第三人称单数用has，其他人称用have 。 hydrogen oxidation sodium solution (about 5%) in the and to just is micro-alkaline, then with distilled water diluted to scale, mixed uniform. this liquid as into Hou restore sugar of stay measuring liquid. 2.2.2 titration: glucose, the same operation. 2.2.3 titration: according to 3.8.3.2.3 the same operation. 2.3 results of calculations and reducing sugar content after conversion (13): X= (ax4000) ? (Vxm) (13) in the formula: X--content of reducing sugars in the sample (in terms of invert sugar),%; A--Rhine-Ed sugar scale (see table 5) found that reducing sugar consumption coefficient of liquid invert sugar corresponding to the product to be tested. F--concentration of fehling solution; V--reducing sugar consumption be measured by the time drops by volume, mL; M--sample mass, g. parallel test results allow errors to 0.5%. Sucrose content by type (14): X= (A-B) x0.9 (14): x--of sucrose content,%; A--transformed the reducing sugar content,%; Before B--into the reducing sugar content,%. Note: in case of dispute, the arbitration law of potassium ferricyanide law. Ash hydroxymethyl furfural by 1 1.1 reagents and materials, except as otherwise provided, the reagents are pure, to distilled water. 1.1.1 barbituric acid solution: weigh 500mg barbituric acid in a beaker of plus 70mL distilled water placed on the hot tub heating mixing the solution, cooled and moved into the 100mL volumetric flask, (三)句型 1、肯定句:主语+have /has+动词过去分词+其他。 I have studied English for 5 years . 2、否定句:主语+have /has+not +动词过去分词+其他。 We haven’t been there . 3、一般疑问句:Have/Has+主语+动词过去分词+其他, Has he eaten that apple ? 4、特殊疑问句:特殊疑问词+ have /has +主语+动词过去分词+其他, (四)时间状语 yet,already,just,never,ever,so far,by now,since+时间点，for+时间段，recently, lately, in the past few years, etc. (五)用法 1、现在完成时可以用来表示发生在过去某一时刻的、持续到现在的情况, 常与for, since连用。 e.g. Mary has been ill for three days. I have lived here since 1998. 2、现在完成时往往同表示不确定的过去时间状语连用, 如already, yet, just, before, recently, lately等: e.g. He has already obtained a scholarship. I haven’t seen much of him recently (lately). We have seen that film before. Have they found the missing child yet? 3、现在完成时常常与表示频度的时间状语连用，如often, sometimes, ever, never, twice, on several occasion等: e.g. Have you ever been to Beijing? I have never heard Bunny say anything against her. I have used this pen only three times. It is still good. George has met that gentleman on several occasions. 4、现在完成时还往往可以同包括现在时间在内的时间状语连用，如now, up to these few days/weeks/months/years, this morning/week/month/year, now, just, today, up to present, so far等。 e.g. Peter has written six papers so far. Man has now learned to release energy from the nucleus of the atom. There has bee too much rain this year. The relations between us have been enhanced in the past few years. Up to the present everything has been successful. 5、现在完成时表示现在之前就已完成的动作, 虽然其效果或影响仍然存在 但已不再继续, 但是有一些现在完成时的句子，在后面加上for+一段时间，则现 在完成时的动作就表示延续性。 e.g. Thomas has studied Russian. (现在不再学俄语) Thomas has studied Russian for three years. (=Thomas began to study Russian three years ago, and is still studying it now.) 6、现在完成时还可以用来表示过去的一个时间到现在这段时间内重复发生 的动作。 hydrogen oxidation sodium solution (about 5%) in the and to just is micro-alkaline, then with distilled water diluted to scale, mixed uniform. this liquid as into Hou restore sugar of stay measuring liquid. 2.2.2 titration: glucose, the same operation. 2.2.3 titration: according to 3.8.3.2.3 the same operation. 2.3 results of calculations and reducing sugar content after conversion (13): X= (ax4000) ? (Vxm) (13) in the formula: X--content of reducing sugars in the sample (in terms of invert sugar),%; A--Rhine-Ed sugar scale (see table 5) found that reducing sugar consumption coefficient of liquid invert sugar corresponding to the product to be tested. F--concentration of fehling solution; V--reducing sugar consumption be measured by the time drops by volume, mL; M--sample mass, g. parallel test results allow errors to 0.5%. Sucrose content by type (14): X= (A-B) x0.9 (14): x--of sucrose content,%; A--transformed the reducing sugar content,%; Before B--into the reducing sugar content,%. Note: in case of dispute, the arbitration law of potassium ferricyanide law. Ash hydroxymethyl furfural by 1 1.1 reagents and materials, except as otherwise provided, the reagents are pure, to distilled water. 1.1.1 barbituric acid solution: weigh 500mg barbituric acid in a beaker of plus 70mL distilled water placed on the hot tub heating mixing the solution, cooled and moved into the 100mL volumetric flask, e.g. We have had four texts this semester. 现在完成时中的时间状语: ?already通常用于肯定句中，意为“已经”，位于行为动词之前, be动词、助动词之后。有时可放在疑问句句尾，表示惊讶。例如: We have already cleaned the classroom. Have you finished it already, ?yet用于疑问句中表示“已经”;用于否定句中，表示“还(没)”。例如: —Has he found his watch yet,他还没找到他的表吗, —No, not yet. 是, 还没有。 ?ever意为“曾经”，常用于疑问句或否定句中，位于助动词和过去分词之间，表示从过去到目前为止的时间。例如: Have you ever been there,你曾经去过那里吗, Nothing has ever happened here. 这里未曾发生过什么事。 ?never意为“(曾经)从未、没有”, 是否定副词，在句中位于助动词和过去分词之间。ever与否定词not连用相当于never。例如: I haven’t ever spoken to her. = I have never spoken to her. 我从未跟她讲过话。 ?just意为“刚刚”, 用于现在完成时, 表示行为刚刚过去, 位于助动词与过去分词之间。 e.g. He has just come back from school.他刚从学校回来。 ust now意为“刚才”, 表示过去某时, 用于一般过去时, 位于句首或句尾均? j 可。e.g. He came from school just now.他刚才从学校回来。 ?for 和since的用法及区别。for 与一段时间连用，since 与时间点连用。 注意:since 后接过去时的时间状语或过去时的句子。 e.g. I have been to Shanghai twice since 1970. I haven’t seen her since she left Shanghai. I saw Ping Ping six years ago. Since I havenever seen her. ?have/has gone to、have/has been to 和have/has been in的区别。 have/ has gone to 去了,在去某地的路上或在某地, 人还未回来 have/ has been to 曾经去过, 人已经回来了 have/ has been in 已经在, 常与一段时间连用 e.g. She has been to Shanghai before. 她以前曾去过上海。 She has been in Shanghai for ten years. 她在上海10年了。 Has he gone to Qingdao? 他去青岛了吗, 但不能说 Have you gone to Qingdao? 一般过去时与现在完成时的转换 在现在完成时中，延续性动词能与表示一段时间的状语连用，瞬间动词却不能。但是，可用别的表达方式: ?瞬间动词用于“一段时间 + ago”的一般过去时的句型中; ?瞬间动词可改成与之相对应的延续性动词及短语，与一段时间连用; ?瞬间动词用于“It is + 一段时间 + since + 一般过去时”的句型中，表示“自从……以来有……时间”的意思，主句一般用it is来代替It has been; ?瞬间动词用于“Some time has passed since + 一般过去时”的句型中。请看: hydrogen oxidation sodium solution (about 5%) in the and to just is micro-alkaline, then with distilled water diluted to scale, mixed uniform. this liquid as into Hou restore sugar of stay measuring liquid. 2.2.2 titration: glucose, the same operation. 2.2.3 titration: according to 3.8.3.2.3 the same operation. 2.3 results of calculations and reducing sugar content after conversion (13): X= (ax4000) ? (Vxm) (13) in the formula: X--content of reducing sugars in the sample (in terms of invert sugar),%; A--Rhine-Ed sugar scale (see table 5) found that reducing sugar consumption coefficient of liquid invert sugar corresponding to the product to be tested. F--concentration of fehling solution; V--reducing sugar consumption be measured by the time drops by volume, mL; M--sample mass, g. parallel test results allow errors to 0.5%. Sucrose content by type (14): X= (A-B) x0.9 (14): x--of sucrose content,%; A--transformed the reducing sugar content,%; Before B--into the reducing sugar content,%. Note: in case of dispute, the arbitration law of potassium ferricyanide law. Ash hydroxymethyl furfural by 1 1.1 reagents and materials, except as otherwise provided, the reagents are pure, to distilled water. 1.1.1 barbituric acid solution: weigh 500mg barbituric acid in a beaker of plus 70mL distilled water placed on the hot tub heating mixing the solution, cooled and moved into the 100mL volumetric flask, A. He joined the League two years ago. B. He has been in the League for two years. C. It is two years since he joined the League. D. Two years has passed since he joined the League. 八、过去完成时 (一)过去完成时的概念 过去完成时表示过去某一时间或某一事件之前已经发生的动作或状态，即 过去的过去。图示如下: ----|-------------------------- |---------------------------|-----------------------> 过去完成 过去 现在 将来 (二)构成 1、肯定句:主语+had，过去分词 When we got there, the football match had already started. 2、否定句:主语+had not+过去分词 He hadn’t worked for two years by then. 3、疑问句:had+主语+过去分词…, Had he finished the work by last month? (三)时间状语 Before, by the end of last year (term, month…), etc. (四)用法 1、过去完成时表示过去某一时刻或者某一动作之前完成的动作或状态; 句中常用by, before, until, when等词引导的时间状语。 e.g. By the time she got up, her brother had already gone into the bathroom. 2、过去完成时的动词还可以表示过去某一时刻之前发生的动作或者状态 持续到过去某个时间或者持续下去。例如: Before he slept, he had worked for 12 hours. 3、在told, said, knew, heard, thought等动词后的宾语从句。例如: She said (that) she had never been to Paris. 4、在过去不同时间发生的两个动作中，发生在先，用过去完成时;发生 在后，用一般过去时。例如: When the police arrived, the thieves had run away. 5、by the time “直到……时候”。指从过去某一点到从句所示的时间为止 的一段时间。如: By the time we got to his house, he had finished supper. 6、表示意向的动词, 如hope, wish, expect, think, intend, mean, suppose等, 用过去完成时表示 “原本…，未能…”。例如: We had hoped that you would come, but you didn't. 针对性练习:(见课后资料) hydrogen oxidation sodium solution (about 5%) in the and to just is micro-alkaline, then with distilled water diluted to scale, mixed uniform. this liquid as into Hou restore sugar of stay measuring liquid. 2.2.2 titration: glucose, the same operation. 2.2.3 titration: according to 3.8.3.2.3 the same operation. 2.3 results of calculations and reducing sugar content after conversion (13): X= (ax4000) ? (Vxm) (13) in the formula: X--content of reducing sugars in the sample (in terms of invert sugar),%; A--Rhine-Ed sugar scale (see table 5) found that reducing sugar consumption coefficient of liquid invert sugar corresponding to the product to be tested. F--concentration of fehling solution; V--reducing sugar consumption be measured by the time drops by volume, mL; M--sample mass, g. parallel test results allow errors to 0.5%. Sucrose content by type (14): X= (A-B) x0.9 (14): x--of sucrose content,%; A--transformed the reducing sugar content,%; Before B--into the reducing sugar content,%. Note: in case of dispute, the arbitration law of potassium ferricyanide law. Ash hydroxymethyl furfural by 1 1.1 reagents and materials, except as otherwise provided, the reagents are pure, to distilled water. 1.1.1 barbituric acid solution: weigh 500mg barbituric acid in a beaker of plus 70mL distilled water placed on the hot tub heating mixing the solution, cooled and moved into the 100mL volumetric flask,