动词是表示动作（jumped, shows）和状态的词性（are, was）。
动词是句子的核心。关于如何提高运用动词的能力，特别是当你不理解文章中被标示出来的错误时，你可以请教你的老师。
助动词
助动词要放在主动词的前面。下面的这些词都是助动词：
be, am, is, are, was, were, being, been, has, have, had,
do, does, did, can, will, shall, should, could, would,
may, might, y must.
忽略助动词的使用会造成句子错误：
Many people don't know what they going to do after graduation.
I going to give step-by-step instructions.
在第一句中“they going”应该改为是“they are going”。在第二句话中“I going” 应该是“I am going”。确保主动词和助动词的正确形式。下面的句子应该怎样修改呢？
They are go to a four-year college.
The rules should always be maintain.
没错，在第一个例句中，主动词形式应改为“going”，第二句中主动词的正确形式为“maintained”。
助动词后面不要用“of”。
一些动词短语中会出现两个或两个以上的动词（should have happened, might be eaten, could have decided）。
下面是几个用了“of”的句子：
They would of stayed one more month if possible.
In that time, he could of finished the project.
“Of”是一个介词，不是动词。在上面的例句中，“of”应该改为助动词“have”。
确保助动词使用正确。
助动词might, must, can, would和should用来表达限制动作或状态的条件。如下面的两个例子；
I might have gone to the party if I had been invited.
If I were the president of the United States, I would support expanding our railroad system.
助动词可以用来表达与现实相反的愿望，如：
I wish that we had not lost that album of family photographs.
助动词还可以表示在特定时间段内完成或发生的动作。助动词“had”和“have”可以体现两个动作发生的时间顺序。例如，在这个句子中，“looking”发生在过去，并且发生在“finding”之前：
I had looked at several computer games before I found this one.
下面这句话表达了正在发生而且将持续一段时间的动作：
I am looking at several computer games and trying to decide which one I like best.
下句中的助动词表达了希望这个动作在将来的某个时刻完成：
I will have completed my search by end of the school year because I want to play my new game with my cousins when they visit.
核实是否正确使用了动词的不定式形式。
不定式是动词的基本形式。动词的其它时态都是由不定式演变而来。不定式是由“to”加/动词原形构成的。下面例句中的动词不定式形式是不正确的：
Soil works as a sponge to holds water.
He wanted to spent time with his family.
第一个例句中不定式应该是“to hold”而在第二个例句中应该是“to spend”。
用动词不定式来表示与主动词表示的动作在同一时间发生，或紧随其后发生的动作。
I like to play video games.
这句话中动作“liking”是和 “playing”同时发生的。
Verbs are parts of speech that express action (jumped, shows) or a state of being (are, was).
Verbs are the heart of a sentence. Get your instructor's advice on improving your use of verbs, especially if you don't understand the highlighted verb errors in your essay.
Helping Verbs
Helping verbs (or auxiliary verbs as they are sometimes called) precede the main verb. All of these are helping verbs:
be, am, is, are, was, were, being, been, has, have, had,
do, does, did, can, will, shall, should, could, would,
may, might, and must.
Overlooking helping verbs can ruin your sentences:
Many people don't know what they going to do after graduation.
I going to give step-by-step instructions.
In the first sentence, "they going" should be "they are going." In the second, "I going" should be "I am going." Make certain that you use the correct form of the main verb with the helping verb. How would you improve these sentences?
They are go to a four-year college.
The rules should always be maintain.
Yes, the main verb form should be "going" in the first example and "maintained" in the second example.
Make sure you do not use of after a helping verb.
In some verb phrases, there are two or more verbs being used (should have happened, might be eaten, could have decided). Here are examples in which the word "of" was used:
They would of stayed one more month if possible.
In that time, he could of finished the project.
"Of" is a preposition, not a verb, and in each of these sentences "of" should be replaced with the helping verb "have."
Make sure you use helping verbs correctly.
Verbs such as might, must, can, would, and should are helping verbs that express conditions that restrict an action or being. Here are two examples:
I might have gone to the party if I had been invited.
If I were the president of the United States, I would support expanding our railroad system.
Helping verbs must be used to express a wish that is contrary to the facts as in this example:
I wish that we had not lost that album of family photographs.
Helping verbs also indicate action completed or occurring at a specific time. Helping verbs such as "had" and "have" show the relationships between two actions in time. For example, in this sentence, the "looking" happened in the past before the "finding" happened:
I had looked at several computer games before I found this one.
Here the action is happening and will probably happen for some time:
I am looking at several computer games and trying to decide which one I like best.
Here the action is expected to be completed by some future time:
I will have completed my search by end of the school year because I want to play my new game with my cousins when they visit.
Make sure you use the infinitive form of the verb correctly.
The infinitive is the basic form of every verb, and it is from the infinitive that all other verb tenses come. The infinitive is formed by using the word "to" plus the present tense form of the verb. In the following sentences there are incorrectly formed infinitives:
Soil works as a sponge to holds water.
He wanted to spent time with his family.
The infinitive should be "to hold" in the first sentence and "to spend" in the second sentence.
Use infinitives to show action that is occurring at the same time as, or later than, the action of the main verb.
I like to play video games.
This sentence means that the "liking" is happening at the same time as the "playing."