2.1.1 动词变化题 Verb Tense, Voice & Mood（★★★★★）
出题频率约5.4%，每套题目中出现2~3题。
考点速递
动词时态
典型题例：时态题考查动词的各种时态变化，所以可以从选项中判断，一般来说选项中会出现同一动词的各种时态变化。如下面的题目：
Nutritionists consider Greek yogurt to be a healthy food: it is an excellent source of calcium and protein, serves as a digestive aid, and it contains few calories in its unsweetened low- and non-fat forms.（OG Test 1-8）
A. NO CHANGE
B. containing
C. contains
D. will contain
做题步骤：时态是动词考查频率最高的考点，对于动词时态题来说，要掌握三个关键的步骤：
第一，看选项。观察四个选项可发现，它们都是某个动词的时态变化。
第二，观察动词所在的句子的句型。根据句型来确定这个动词与句中其他动词的关系。
第三，认清时间状语和句意。根据时间状语和句子意思来判断动作发生的时间，确定动词的时态。此处要注意某些动词的不规则变化，尤其是动词的过去式（did）和过去分词（done）形式。
下面我们用OG的例题来说明一下这种题的解题方法。
Nutritionists consider Greek yogurt to be a healthy food: it is an excellent source of calcium and protein, serves as a digestive aid, and it contains few calories in its unsweetened low- and non-fat forms.（OG Test 1-8）
A. NO CHANGE
B. containing
C. contains
D. will contain
解析：
1）看选项。四个选项都是contain一词的时态变化，属于时态题。
2）观察句型。句型为and连接的并列联句，前后两句为并列关系。
3）认识时间状语和句意。本句没有明显的时间状语。句子解释的是同一事物（Greek yogurt）的营养特征，属于普遍存在的事实，所以前后都应该用一般现在时。
答案：C
介绍了基本的做题方法之后，我们具体介绍一下六种最常考的时态及它们的适用情况，以便各位考生在做题时能迅速找到各个时态常见的句型和时间状语。
1. 一般现在时（present tense）
表示经常发生的事件（如每天都做的事情），或者存在性的事件（客观事实、领土领空等），不强调发生的具体时间。在考查时，通常用过去时或者现在进行时作为干扰选项。
误：More than half of the states in US is extending farther north than Canada's southernmost point.（SAT ）
正：More than half of the states in US extends farther north than Canada's southernmost point.
译文：美国有超过一半的州地理位置都在加拿大最南端以北。
解析：按照句子意思，这句话涉及的是领土的位置，那么这种情况是存在性的事件，没有发生的具体时间，不存在正在发生的情况，所以使用一般现在时。
2. 一般过去时（past tense）
表示在过去的时间做的事情，以及意义上发生在过去的事情。
两类词对过去时态有较强的提示作用，一类是时间状语，另一类是时间状语从句连接词。过去时的时间状语包括过去的具体时间（in the 1930s）、ago短语、last短语等。这些词出现时，提示句子发生的背景时间，一般用过去时。
误：In the 1920s, the Beechnut Packing Company, wanting to boost its sales of bacon, hires a repute expert in public relations named Edward Bernays.
正：In the 1920s, the Beechnut Packing Company, wanting to boost its sales of bacon, hired a repute expert in public relations named Edward Bernays.
译文：20世纪20年代，Beechnut Packing公司想要增加培根的销量，于是雇用了一位很有名的公关专家，叫Edward Bernays。
解析：本句应该使用过去时态，因为有过去的具体时间in the 1920s，“雇用”这个动作发生在过去，就应该使用一般过去时。
除了时间状语之外，部分时间状语从句也有提示作用。一般来说，考查一般过去时的从句中会含有when、while、as、at the same time、at the moment等表示“同时”意义的词，这样主从句中有一句用一般过去时态的话，另外一句按照句意也会使用同样的时态——一般过去时。
误：The mission was purposely ended when the Galileo disintegrates in the dense atmosphere of the Jupiter.
正：The mission was purposely ended when the Galileo disintegrated in the dense atmosphere of the Jupiter.
译文：当伽利略号在木星浓密的大气层中解体时，这个任务就结束了。
解析：因为有when从句，那么说明主句和从句发生的时间是一致的，当主句用过去时was ended的时候，从句的动作也应该用过去时disintegrated。
但是也要注意，并不是只要句子中出现表示过去的时间状语就用过去时，要分清楚动词所表示的动作是不是发生在这个时间。比如说下面的句子中，虽然有表过去的时间状语，但stipulate并不用过去时。
Enacted in 1972 as part of the Education Amendment to the Civil Rights Act of 1964, Title IX stipulates that no person shall be excluded from any arenas of public schooling on the basis of sex.（ACT 71H，2014.4）
这句话中用一般现在时stipulates是正确的。很多考生会因为前面的in 1972这个时间而判定后面的动词stipulate用过去时，实际上in 1972是指enact这个动作发生的时间，而stipulate是“规定，约定”的意思，指的是Title IX的内容，也就是一种存在性的事实，用一般现在时最好。
3. 现在进行时（present continuous）
表示现在正在进行的事件，要区分它与一般现在时的区别。
误：The labor union is negotiated a contract with the hospital.
正：The labor union is negotiating a contract with the hospital.
译文：工会正在和医院商讨一个协议。
解析：表示现在正在进行的动作，用现在进行时，注意不要与一般现在时混用。
4. 现在完成时（present perfect）
表示到现在为止已经完成的动作，常与since、so far、for ten days、recently这类短语搭配。
误：Hawaii's green sea turtle was classified as an endangered species for over 25 years.
正：Hawaii's green sea turtle has been classified as an endangered species for over 25 years.
译文：夏威夷的绿海龟已经被列为濒危品种超过25年了。
解析：因为句子中含有时间状语for over 25 years，所以动词应该使用现在完成时has been classified。
5. 过去完成时（past perfect）
表示到过去某一时间为止已经完成的动作，或者过去的某件事之前已经在做的事情。常与“by+过去时间”“before+过去时间”的时间状语连用。
误: Traffic was heavy, so by the time Brianne finally arrived at the theatre, we waited for her for an hour, missing the first act of the play.
正：Traffic was heavy, so by the time Brianne finally arrived at the theatre, we had waited for her for an hour, missing the first act of the play.
译文：路上车很多，所以当布莱尼最终到达剧院的时候，我们已经等了她一个小时，把整个剧的第一幕都错过了。
解析：在句子中，布莱尼到达剧院的时间是过去，到过去的这个时间为止，“等待”这个动作已经做了一个小时，所以应该用过去完成时。
6. 过去将来时（past future）——在过去的基础上讲未来
过去将来时表示从过去的某一时间来看将来要发生的动作或呈现的状态。过去将来时常用于宾语从句和间接引语中。过去将来时的出发点是过去，即从过去某一时刻看以后要发生的动作或状态。表示过去认为“将来会怎么样”，这个“将来”就是“过去的将来”。过去将来时的一般形式为would do。
误：Mr. Lee and his grandchildren practiced traditional Chinese calligraphy together so that the children know an art cherished by earlier generations of their family.
正：Mr. Lee and his grandchildren practiced traditional Chinese calligraphy together so that the children would know an art cherished by earlier generations of their family.
译文：李先生和他的孙子女一起练习书法，希望他们将来能够了解这个一直被家族珍视的传统。
解析：在这句话中，practiced这个动作用的是过去时，那么以这个时间为基础，将来发生的事情就是用would know这一过去将来时。
知己知彼
考题速递
1. According to Box, a leading Greenland expert, tundra fires in 2012 from as far away as North America produced great amounts of soot, some of which drifted over Greenland in giant plumes of smoke and then fell as particles onto the ice sheet.（OG Test 1-18）
A. NO CHANGE
B. falls
C. will fall
D. had fallen
解析：1）看选项。四个选项都是fall一词的时态变化，属于时态题。
2）观察句型。句型为and连接的并列联句，前后两句为并列关系。
3）认识时间状语和句意。本句中的时间状语为in 2012，表示过去，所以句子中drifted和fell都用一般过去时。
答案：A
2. In addition, the number of four-year graduates in philosophy has grown 46 percent in a decade. Also, studies have found that those students who major in philosophy often do better than students from other majors in both verbal and analytical writing as measured by standardized test scores. On the Graduate Record Examination（GRE）, for example, students intending to study philosophy in graduate school has scored higher than students in all but four other majors.（OG Test 1-40）
A. NO CHANGE
B. have scored
C. scores
D. scoring
解析：1）看选项。四个选项都是score一词的时态变化，属于时态题。
2）观察句型。句型为简单句，所以要根据其前后句的时态来判定。
3）认识时间状语和句意。本句没有明显的时间状语。按照句意，第一句中的“in a decade”（在过去的十年里）限定了“哲学专业学生数量增长”“研究发现”这两件事的时间，所以动词用现在完成时“has grown”和“have found”。按照句意，那些学哲学的学生在GRE考试中分数比其他四个专业的高这件事也是研究的一部分，和研究一样，都是发生在过去十年中，所以也应该用现在完成时，然后结合本句主语的中心词students，可以确定动词要用复数形式。
答案：B
3. Like any other health problems, these ailments can increase employee absenteeism, which, in turn, is costly for employers.（OG Test 3-5）
A. NO CHANGE
B. are
C. is being
D. have been
解析：1）看选项。四个选项都是be一词的时态变化，属于时态题。
2）观察句型。句型为which引导的定语从句，对increase起补充说明作用。
3）认识时间状语和句意。本句没有明显的时间状语。be costly这个动作是对前面can increase的补充说明，两个动词都是these ailments发出的，意义上应该为同一时态，所以使用一般现在时。
答案：B
4. Not all research into regional English varieties requires such time, effort, and resources, however. Today's researchers have found that the veritable army of trained volunteers traveling the country conducting face-to-face interview can sometimes be replaced by another army: the vast array of individuals volunteering details about their lives—and, inadvertently, their language—through social media.（OG Test 4-28）
A. NO CHANGE
B. are requiring
C. have required
D. require
解析：1）看选项。四个选项都是require一词的时态变化，属于时态题。
2）观察句型。句型为简单句。
3）认识时间状语和句意。本句没有明显的时间状语。句子要说明普遍存在的情况，用一般现在时。主语research为单数，用单数谓语。
答案：A
5. There were a number of steps you can take to determine whether game design is the right field for you and, if it is, to prepare yourself for such a career.（OG Test 4-34）
A. NO CHANGE
B. has been
C. are
D. was
解析：1）看选项。四个选项都是be一词的时态变化，属于时态题。
2）观察句型。句型为there be结构的简单句。
3）认识时间状语和句意。本句没有明显的时间状语。句子要说明的是普遍存在几个步骤来确定游戏策划是否适合“你”，所以应该用一般现在时。
答案：C
6. Its ability to thrive out of the water as well as in it stem largely from certain physical adaptations that are generally not observed in other fish.（2016. 3-2）
A. NO CHANGE
B. stems
C. stemmed
D. have stemmed
解析：1）看选项。四个选项都是stem一词的时态变化，属于时态题。
2）观察句型。句型是Its ability为主语的简单句。
3）认识时间状语和句意。本句没有明显的时间状语。句子解释的是鱼类能跳出水面的能力，是存在性的事实，应该使用一般现在时。
答案：B
7. As I enter the central gallery of the Arms and Armor collection at the Metropolitan Museum of Art in New York City, an imposing array of heraldry flags flies above me, each flag is bearing a coat of arms.（2016. 3-12）
A. NO CHANGE
B. are bearing
C. bearing
D. bears
解析：1）看选项。四个选项都是bear一词的时态变化，属于时态题。
2）观察句型。as作为连词，连接时间状语从句和主句。
3）认识时间状语和句意。本句没有明显的时间状语。分句为“As I enter...”，主句为“an imposing array of heraldry flags flies...”，主从句各有谓语动词（enter和flies），所以each flag后面的bear不能再使用谓语动词形式，应该使用bearing做伴随状语。
答案：C
8. Though the armor is empty, each complete suit has been assembled to create the illusion that it is inhabited. The illusion is a powerful one, but the exhibit offers more than just fantasy.（2016. 3-13）
A. NO CHANGE
B. was
C. has been
D. had been
解析：1）看选项。四个选项都是be一词的时态变化，属于时态题。
2）观察句型。句型为that引导的定语从句，修饰illusion。
3）认识时间状语和句意。本句没有明显的时间状语。由于“it is inhabited”这一事件并没有发生过，所以不能使用过去时和完成时。应该使用一般现在时描述一种状态。
答案：A
动词的单复数
主谓一致是指句子的主语和谓语的单复数要一致。主语（subject）一般由名词充当，谓语一般由动词充当。SAT 经常考查这个考点。
基本的主谓一致问题
主谓一致这一考点最重要的解题方法就是要找到主语的中心词，根据中心词的单复数来选择相应的谓语动词。一般情况下，主语应该是句子开头最早出现的独立名词或名词性短语。但是在新SAT考试中，这些名词通常不是独立出现的，而是常常带有很多的修饰成分，所以要找到主语的中心词，就要先学会划掉主语的修饰成分（trim the fat）。主语的修饰成分可分为以下四种。
1. 介词短语：由介词加名词构成，介词短语是主语的修饰成分，对主语的单复数没有影响，在判断主谓一致时可以划掉。
That book on political parties is interesting.
Julie, along with her friends, is planning to go to the cinema.
常见的介词
2. 定语从句：用来描述或补充说明主语中心词，对中心词的单复数没影响，可以划掉。
The books I bought at the bookstore were expensive.
The student that the headmaster picked up from Class Two was John.
3. 后置定语（doing/done短语）做修饰成分，对中心词的单复数没有影响，可以划掉。
A few daring students, led by a senior who would–miraculously graduate a few months later, were playing leapfrog outside the window of a room where cameramen were recording the dean's lecture.（Khan Academy language use: Subject-Verb agreement 50）
4. 主语后面的插入语处于主语与谓语之间，对主语的单复数没影响，可以划掉。
The first large predators on Earth, according to at least one source, were sea scorpions that grew up to almost six feet in length.（Khan Academy language use: Subject-Verb agreement 30）
特殊主语：
1. 动名词做主语时，谓语动词用单数形式。
Growing flowers is her hobby.
2. 抽象名词做主语时，谓语动词用单数形式。
The transportation in Shenzhen is very poor.
3. 表示单数意义的词，形容词every、each，以及相关的词组every one of、each of等都要搭配使用单数谓语。另外，相关的不定代词要使用单数谓语。
Every man, woman, and child needs love.
Every one of my friends is here.
None of the boys is here.
4. 专有名词或名称，格式上表现为斜体和首字母大写的，如The New York Times，谓语动词用单数。
The New York Times is an American daily newspaper founded and continuously published in New York City since 1851.
5. the number做主语时，谓语动词用单数形式。若是a number of（表示“许多”）引导的短语做主语，之后的名词和谓语动词都用复数形式。
The number of students in the class is fifteen.
A number of students were late for class.
6. 主语中含有a group of、a team of、a sequence of、a list of等短语，谓语动词用单数形式。
A group of professors, highly respected for their knowledge, is welcomed as consultants of the institution.
特殊句型：
1. 倒装句：谓语放在主语的前面的句子。
Across the river and the trees stands an old lady.
Among his most famous things is his collection of CD's.
2. there be句型中，be的单复数是由be后面的名词的单复数来决定的。
There are colorful birds everywhere in the forest.
典型题例：
Anyone who has traveled to foreign countries understand the importance of getting immunization shots.
A. NO CHANGE
B. understands
C. have understood
D. were understanding
通过选项能够看出，四个选项均为动词，动词的单复数有所不同，其中ACD选项为复数形式，B选项为单数形式。本题考查动词的单复数。
解析：
1）看选项：根据选项确认本题需要判断动词understand的单复数。
2）trim the fat：去掉who has traveled to foreign countries这个从句，判断主语的中心词为anyone。
3）特殊主语或特殊句型：anyone一词为不定代词，意义为“任何一个”，同everyone、no one、some one一样，与之搭配的谓语用单数。
答案：C
知己知彼
真题速递
1. These Harvey Houses, which constituted the first restaurant chain in the United States, was unique for its high standards of service and quality.（OG Test 3-15）
A. NO CHANGE
B. were unique for their
C. was unique for their
D. were unique for its
解析：1）看选项：选项中含有was、were，表明本题要区分谓语动词单复数。
2）trim the fat：去掉which从句，找到主语的中心词These Harvey Houses，谓语动词用复数were。
3）句中含有代词its和their的区分，由于此处指代These Harvey Houses，所以应该用复数their。
答案：B
2. Yet some of the earliest known works of art, including paintings and drawings tens of thousands of years old found on cave walls in Spain and France, portrays animals.（OG Test 3-36）
A. NO CHANGE
B. portraying
C. portray
D. has portrayed
解析：1）看选项：选项中含有portray、portrays等单复数形式，这表明本题考查谓语动词单复数。
2）trim the fat：去掉including引导的短语，留下主语some of the earliest known works of art，其中of art修饰中心词some of the earliest known works，所以谓语动词用复数portray。
答案：C
3. According to such organizations as the US Environmental Protection Agency, the minute amounts of residue falling within such limits have no negative impact on human health.（OG Test 4-19）
A. NO CHANGE
B. is having
C. has had
D. has
解析：1）看选项：选项中含有have、is、has，表明本题考查谓语动词单复数。
2）trim the fat：去掉介词短语of residue，留下主语中心词the minute amounts，所以谓语动词用复数have。
答案：A
4.“We only have three weeks until our fall issue goes to print,” say Elena as a reminder to the Life and Art Magazine editors who lagged on deadlines.（Khan Academy language use: Subject-Verb agreement 2）
A. NO CHANGE
B. were saying
C. have said
D. said
解析：1）看选项：根据选项可知本题需要判断动词say的单复数。
2）trim the fat：去掉as a reminder to the Life and Art Magazine editors，找到主语的中心词Elena。
3）特殊主语或特殊句型：此处为对话的引用，“say Elena as a reminder to the Life and Art Magazine editors”用的是倒装结构，正常语序应该是“Elena say as a reminder to the Life and Art Magazine editors”，主语Elena为单数，排除A、B、C选项。
答案：D
5. Writing have been invented in Sumer around 3200 B.C., making the beginning of recorded history.（Khan Academy language use: Subject-Verb agreement 6）
A. NO CHANGE
B. was
C. were being
D. are
解析：1）看选项：根据选项可知本题需要判断系动词be的单复数。
2）特殊主语或特殊句型：本题的主语比较简单，动名词writing做主语，根据“动名词做主语需要使用单数谓语”的规则，排除A、C、D选项。
答案：B
6. Awarded a Newbery Medal, Doll Bones are the story of three children's quest to return a haunted doll to its proper grave site.（Khan Academy language use: Subject-Verb agreement 7）
A. NO CHANGE
B. is
C. were
D. have been
解析：1）看选项：根据选项可知本题需要判断系动词be的单复数。
2）trim the fat：去掉Awarded a Newbery Medal这个定语，判断主语的中心词为Doll Bones。
3）特殊主语或特殊句型：Doll Bones一词为斜体形式，且首字母大写，根据格式可以看出这是一个专有名词。根据句意判断Doll Bones是一个“story”的名字，所以应该作为单数处理，搭配单数的谓语动词。
答案：B
7. With the help of the Mat-Su Regional Medical Center, middle school students in Gateway, Alaska observe intubation and sets bones.（Khan Academy language use: Subject-Verb agreement 11）
A. NO CHANGE
B. is setting
C. has set
D. set
解析：1）看选项：根据选项可知本题需要判断动词set的单复数。
2）trim the fat：去掉“in Gateway，Alaska”这个介词短语，判断主语的中心词为middle school students。
3）特殊主语或特殊句型：题目本身是一个平行结构的句子，主语为复数，observe intubation 和sets bones两个短语应该平行，使用同样的单复数和时态。
答案：D
8. Although calzones often contain the same ingredients as pizza, they are much easier to hold and present a much more subdued package.（Khan Academy language use: Subject-Verb agreement 15）
A. NO CHANGE
B. contains
C. is containing
D. has contained
解析：1）看选项：根据选项可知本题需要判断动词contain的单复数。
2）trim the fat：本题结构简单，主语的中心词为calzones，形式为复数。
3）注意：calzone一词意为“半圆形烤馅饼”，当不认识calzone一词，不能判断它的单复数时，可以参照文中的代词“they”（指代calzones）来判断。
答案：A
9. A recent experiment revealed that hungry mosquitoes first hones in on smell and then on warmth, thus body odor may play a key role in being more desirable to the bugs.（Khan Academy language use: Subject-Verb agreement 16）
A. NO CHANGE
B. is first honing
C. first hone
D. has first honed
解析：1）看选项：根据选项可知本题需要判断动词hone的单复数。
2）trim the fat：hone的主语应该是hungry mosquitoes，注意不要错看为A recent experiment。
答案：C
10. Despite claims that Columbus's journey to the Americas was filled with harsh weather, records show that the seas were fairly calm for the duration of the trip.（Khan Academy language use: Subject-Verb agreement 17）
A. NO CHANGE
B. shows
C. is showing
D. has shown
解析：1）看选项：根据选项可知本题需要判断动词show的单复数。
2）trim the fat：主语的中心词是records。
3）注意：主语前面的“Despite claims that Columbus's journey to the Americas was filled with harsh weather”只是修饰成分，对主语的单复数没有影响。
答案：A
11. In 1906, President Theodore Roosevelt revised 300 words that was thought to be too complex. The president felt words like honour, centre, and travelled should be simplified, hence the deviation of American spellings from their British counterparts.（Khan Academy language use: Subject-Verb agreement 18）
A. NO CHANGE
B. has been
C. is
D. were
解析：1）看选项：根据选项可知本题需要判断系动词be的单复数。
2）trim the fat：定语从句中，关系代词that应该指代先行词300 words，所以be动词应该使用复数形式。
答案：D
12. “All the President’s Men is the most important work of investigative reporting to come out of the 20th century,” Hannibal said.（Khan Academy language use: Subject-Verb agreement 25）
A. NO CHANGE
B. are
C. were
D. have been
解析：1）看选项：根据选项可知本题需要判断系动词be的单复数。
2）trim the fat：经判断主语是All the President’s Men。
3）特殊主语或特殊句型：All the President’s Men为斜体形式，且每个单词的首字母大写，根据格式可以看出这是一个专有名词。根据句意判断，All the President’s Men是一个“work”的名字，所以应该作为单数处理，搭配单数的动词。
答案：A
13. Everyone in the psychiatric communities I've visited agree that daily exercise can enhance mental well-being.（Khan Academy language use: Subject-Verb agreement 26）
A. NO CHANGE
B. agrees
C. have agreed
D. were agreeing
解析：1）看选项：根据选项可知本题需要判断动词agree的单复数。
2）trim the fat：去掉in the psychiatric communities这个介词短语及后面的修饰性从句“I've visited”，判断主语的中心词为everyone。
3）特殊主语或特殊句型：everyone为不定代词，意义为“每一个”，同anyone、no one、some one一样，谓语用单数。
答案：B
动词语态
典型题例：
“Panama,” a poem by James Jeffrey Roche, was writing to celebrate the construction of the canal which connected to the Atlantic and Pacific oceans.（Khan Academy language use: shifts in verb, tense and mood 21）
A. NO CHANGE
B. will be written
C. was written
D. wrote
通过选项能够看出，四个选项均为动词，动词的语态有所不同，其中A、D选项为主动形式，B、C选项为被动形式。本题考查动词的主被动语态。
做题步骤：
1. 看句意，判断主语和谓语之间的主被动关系。
2. 判断动词的时态和单复数。
“Panama,” a poem by James Jeffrey Roche, was writing to celebrate the construction of the canal which connected to the Atlantic and Pacific oceans.（Khan Academy language use: shifts in verb, tense and mood 21）
A. NO CHANGE
B. will be written
C. was written
D. wrote
解析：1）看句意，判断主被动。句意为：《巴拿马》是詹姆斯·杰佛瑞·罗奇为了歌颂连接大西洋和太平洋的巴拿马运河建成所作的一首诗。诗歌是被写出来的，主谓语之间是被动关系，所以要从B、C选项中选择答案。
2）判断时态和单复数。句子中虽然没有明显的时间状语，但是这首诗已经存在，显然不能使用B选项中的将来时。
答案：C
主动语态指句子的主语是动作的执行者，被动语态指句子的主语是动作的承受者。 动词语态的考点包括两种：一种是区分主被动语态，这种情况可以通过句子意思来进行判断；另一种是考查被动语态的各种时态，这时候要注意被动语态be done中be的各种形式，因为各种时态和其他语法表现在系动词be上。
下面表格中列举了一些比较常用的被动语态的时态形式。
考法1：区分动词的主被动。
例句：
误：The theremin, the first electronic musical instrument, invented in 1918 by Russian physicist, Leon Theremin.
正：The theremin, the first electronic musical instrument, was invented in 1918 by Russian physicist, Leon Theremin.
译文：第一个电子乐器特雷门琴是由俄国物理学家里昂·特雷门在1918年发明的。
解析：根据句意，特雷门琴应该是“被发明”，所以应该用被动语态was invented，而不能使用主动语态invented。
考法2：区分被动语态的时态。
例句：
误：A library with five thousand books are offered to the nation as a gift when Lee Prisa became president.
正：A library with five thousand books was offered to the nation as a gift when Lee Prisa became president.
译文：李·普雷沙当总统的时候，国家收到了一个有5 000本藏书的图书馆作为礼物。
解析：句子中library是offer的承受者，要用被动语态。library是单数形式，with five thousand books是介词短语修饰library，所以句子的谓语也应该是单数。后面的when从句提示我们offer这件事情应该和became president发生在同一时间，所以应该都用一般过去时，故改为was offered。
知己知彼
考题速递
1. The editors of our literary magazine is kept busy all year with a wide variety of tasks.（ACT真题）
A. NO CHANGE
B. keeps
C. are kept
D. has been keeping
解析：1）看句意，判断主被动。根据句意，“我们文学杂志的编辑一整年都被各种事务搞得很忙”，句意为被动，应该使用keep一词的被动形式。
2）判断时态和单复数。句子没有明显的时间状语，表达的是一种常年的状态，所以使用一般现在时，结合主语editors，应该使用复数谓语are kept。
答案：C
2. Nobody knows why the trees of the Crooked Forest（located in West Pomerania, Poland）are bowed out at such strange angles. While some people think that the trees were shaped for a purpose, such as furniture or boat carving, others believe that they were bent by strange weather.（Khan Academy language use: shifts in verb, tense and mood 38）
A. NO CHANGE
B. are shaping
C. had been shaped for
D. be shaped for
解析：1）看句意，判断主被动。句意：“没人知道为什么弯曲森林（坐落在波兰波美拉尼亚西部）的树木会出现奇怪的弯曲现象。有些人认为这些树木是被人们有意弯曲成这样的，为了做家具或小船，也有人认为是天气造成的。”句中树木是被弯曲的，所以时态为被动，排除B选项。
2）判断时态和单复数。句子中有while从句，主句和从句之间是同类事物相对比，应使用相同的时态，参照主句中的were bent，while引导的从句也应使用一般过去时。
答案：A
3. If the two principles come into conflict, deciding whether individual rights or national security is taking priority would be a challenging task.（Khan Academy language use: shifts in verb, tense and mood 44）
A. NO CHANGE
B. has taken
C. should take
D. is taken
解析：1）看句意，判断主被动。句意：“如果个人权利和国家安全相冲突的话，那就很难界定两者哪个应该优先了。”词组take priority是“比……优先”的意思，与主语之间是主动关系，排除D选项。
2）判断时态和单复数。句子中“界定个人权利和国家安全哪个应该优先”这件事是一种设想，并未真正发生，所以不应该用现在进行时或现在完成时，排除A、B两个选项。
答案：C
虚拟语气
典型题例：
If it hadn't been for the lantern shark's ability to glow and camouflage itself as a ray of light in the water, it will have been eaten by the passing tiger shark.（Khan Academy language use: shifts in verb, tense and mood 59）
A. NO CHANGE
B. will be
C. would have been
D. had been
句子是由if引导的从句，画线部分为谓语动词，且“乌鲨要是不能闪闪发光伪装成照进水中的阳光”为虚拟的情况，并不会真正发生。本题考点是虚拟语气。
做题步骤：
1. 查看句子是否为if引导的从句；如果是，查看画线部分是不是主句或从句的谓语动词。
2. 根据句意，确定句子所述情况不会发生。
3. 根据虚拟语气的规则判断句子是对过去、现在还是将来的虚拟，继而选择动词的形式。
If it hadn't been for the lantern shark's ability to glow and camouflage itself as a ray of light in the water, it will have been eaten by the passing tiger shark.（Khan Academy language use: shifts in verb, tense and mood 59）
A. NO CHANGE
B. will be
C. would have been
D. had been
解析：1）观察if从句及所考查谓语动词。本句是含有if引导的从句的复合句，画线部分为主句的谓语。
2）判断句意为虚拟情况。句子中“乌鲨要是不能闪闪发光伪装成照进水中的阳光”为虚拟的情况，并不会真正发生。
3）判断时态。if从句的谓语为hadn't been for，是对过去的虚拟，所以主句谓语应该使用would/should/could/might have done形式来对应。
答案：C
虚拟语气中动词的变化相对复杂，所以只要是提到，考生就会感到有些头大。实际上，虚拟语气变化有限，句型有限，还是比较好判断的。想要做好虚拟语气的题目，主要应注意以下两点：第一，虚拟语气是动词考点，所以无论句型如何变化，只需要选择正确的动词形式即可，不必关注句子其他成分。第二，虚拟语气在考查时会有主句和从句相互呼应，将主从句中的动词形式对照，符合虚拟语气要求的就是正确选项，不用对句子内容做特别深入的分析。下面我们介绍一下虚拟语气考点。
最常见的虚拟语气出现在条件状语从句中，表示说话人的主观愿望和假想，是对事实情况的相反假设，主要有三种情况：
1）与现在的事实相反
if+Sub.+did/were, Sub.+would do
（这里提到的would可换为should、 could、 might，句意不同，但是都符合动词语气变化）
If God gave me another chance, I would tell her: “I love you.”
If I were you, I would take the umbrella.
2）与过去的情况相反
if+Sub.+had done, Sub.+would have done
If he had taken my advice, he would not have made such a mistake.
3）与将来的情况相反
if+Sub.+would do, Sub.+would do
if+Sub.+did/were, Sub.+would do
if+Sub.+were to do/were to be, Sub.+would do
If he would come here tomorrow, I should/would talk to him.
If there were a heavy snow next Sunday, we would not go skating.
If she were to be there next Monday, I would tell her about the matter.
1. 当从句与主句表示的行为发生时间不同时，动词时态要根据它所表示的时间来调整。
If you had followed the teachers' advice, you would be quite all right now.
2. 如果条件从句中有were、had、should 出现，那么可以把if省略。
If you were in my position, what would you do?
→Were you in my position, what would you do?
If it would rain tomorrow, the meeting would be postponed.
→Should it rain tomorrow, the meeting would be postponed.
用介词短语代替条件状语从句，这样的句子如果有假设的情况，也用虚拟语气。
Without air, there would be no living things.
But for the rain, we would have a pleasant journey.
3. 虚拟语气用于表语从句或同位语从句中，主句中如果含有arrange、command、demand、desire、insist、order、propose、request、require、suggest等，那么这些词的后面用“（should+）Verb”。
He suggested that she（should）take the teacher's advice.
He insisted that he（should）take the teacher's advice.
He demanded that we（should）take the teacher's advice.
He ordered that they（should）take the teacher's advice.
知己知彼
考题速递
1. The difference in emojis from manufacturer to manufacturer can lead to major miscommunications. For example, if you are sending an angry face from your phone, it could end up looking like an embarrassed face on your friend's device.（Khan Academy language use: shifts in verb, tense and mood 58）
A. NO CHANGE
B. send
C. if you were the sender of
D. were you to send
解析：1）观察if从句及所考查谓语动词。本句考查的是if从句，画线部分为从句的谓语。
2）判断句意为虚拟情况。句子中“从手机中发出一张生气的图片”为虚拟的情况，并未真正发生。
3）判断时态。主句的谓语为could do的形式，是对现在或者将来的虚拟，所以从句谓语应该使用did/were/were to do/should do形式中的一种，符合条件的为D选项。（值得注意的是，D选项使用了虚拟+倒装形式，原句应该是“if you were to send...”这种句式。）
答案：D
2. If I was Eleanor and had the chance to go to Italy this summer, I would eat only pizza and gelato every day.（Khan Academy language use: shifts in verb, tense and mood 47）
A. NO CHANGE
B. am
C. would be
D. were
解析：1）观察if从句及所考查谓语动词。本句考查的是if从句，画线部分为从句的谓语。
2）判断句意为虚拟情况。句子中“我是埃莉诺，并且这个夏天有机会去意大利”为虚拟的情况，并未真正发生。
3）判断时态。主句的谓语为would do的形式，是对现在或者将来的虚拟，所以从句谓语应该使用did/were/were to do/should do形式中的一种，符合条件的为D选项。
答案：D