Verb is the most important factor of English Grammar. No Sentence can be possible without any Verb. Sometimes in informal English the Verb may be understood. I have already discussed about many other factors like Formation of Sentence, Parts of Speech, Suffix and Prefix, etc. But Verb is the internal force of a Sentence that holds other words arranged together to make a complete Sentence to convey a suitable message.In English Grammar Verb is called ?the soul of the Sentence?. So from the citation its importance can be realized. Besides, Verb is also called ?the Government of the Sentence?. What more does one need to realize the importance of Verb?Verb varies in variety of ways. So if one has the authority over Verb, he must have the authority over English too.To know Verb well we have to know first the Classification of Verb. Without knowing the Classification of Verb, to have a good command in English is absolutely impossible. So it is very much important now to know the different classes of verb.Classification of VerbWhenever we want to classify anything, we must know from what point of view we are going to classify it. Anything may be classified from different point of view. So to understand any classification well one must have to know well the point of view before going to classify.For instance, men can be classified into two classes according to Gender. Again men can be classified on the basis of language, nationality, literacy, religion and so on. On the basis of Gender men are of two classes like ?male? and ?female?. But on the basis of religion or language or nationality men belong to so many different classes. So for any Classification, any particular point of view is very important.On the basis of ObjectWe have already known that generally a Verb has a Subject, and there may be or may not be an Object. And from the point of view of having or not having an Object Verb may be classified into two classes like 1) Transitive Verb and 2) Intransitive Verb.The Verb that takes an Object is called a Transitive Verb. On the other hand, the Verb that does not take any Object is called an Intransitive Verb.To learn English well we have to recognize easily the Transitive Verb and the Intransitive Verb. Otherwise we will fall in some troubles.Suppose, if I am requested to change a Sentence into Passive, I need to know the difference between Transitive Verb and Intransitive Verb. I can never change any Sentence with Intransitive Verb into a Passive so long the Verb is not used transitively.Again, the synonymous words ?say? and ?tell? bear nearly the same meaning but ?say? is always used intransitively taking no Object, Direct or Indirect. On the other hand, we must use ?tell? transitively.?He said to me a story? is quite an incorrect Sentence but ?He told me a story? is a very much correct Sentence. So we know well the Transitive Verbs and Intransitive Verbs.On the basis of meaning expressedAccording to expressing its meaning Verb may also be classified into two classes like 1) Principal Verb and 2) Auxiliary Verb.Most learners know that ?am, is, are? are auxiliary verb. They are running with a wrong conception. In the Sentence, ?He is honest?, ?is? that means the verb ?to be? expressed its meaning and helped no other Verb. So it cannot be a helping Verb or an Auxiliary Verb. In the above mentioned Sentence obviously ?is? is the Principal Verb.Again, in the Sentence, ?He is going?. the Verb ?is? is an Auxiliary Verb because here ?is? expressed no meaning rather it helped the verb ?going? (non-finite form). And ?going?, even being a verb of non-finite form, expressed its meaning. So in the cited Sentence ?going? is the Principal Verb and ?is? is the Auxiliary Verb.So the Verb that expresses its meaning in the Sentence is called the Principal Verb and the Verb that does not expresses its meaning but helps the Principal Verb to express a complete sense of the Sentence is called the Auxiliary Verb.There are certain Verbs that can be used as Auxiliary Verbs. Some of them, having no meaning, are always used as Auxiliary Verb. ?Shall? ?will? ?may? etc are always Auxiliaries.But there are some other Verbs, even having their meaning, that are used in a Sentence as Auxiliary Verb to help other Principal Verb suppressing their own meaning.I do the sum. Here ?do? is Principal Verb.I do not go. Here, ?go? is Principal Verb but ?do? Auxiliary Verb.Maybe we are now clear about Principal Verb and Auxiliary Verb.On the basis of formationNow we will classify Verb from another point of view. A verb may be in different forms. From the point of view of formation of verb we can classify Verb into two classes such as Strong verb and Weak Verb.Verbs often change their forms taking suffixes like ?ed?, ?ing? etc. But some Verbs are changed into Past form or Past Participle form by changing it vowel or spelling.The verbs of which different Forms are formed simply by adding a Suffix are called Weak Verb. When the Forms of Verbs are changed by changing the vowel in it or changing its spelling or by taking different word are call Strong Verb.Strong Verbs:Write Wrote WrittenGo Went GoneDo Did DoneSleep Slept SleptTeach Taught TaughtWeak Verbs:Work Worked WorkedWalk Walked WalkedRead Read ReadKill Killed KilledIt is observed that the Verbs which can be changed easily in a regular way are called Weak Verbs. On the other hand, the Verbs which are hard or difficult to change or are changed in an irregular way are called Strong Verb.But some Verbs like:Hang: Hang Hanged HangedHang Hung HungLie: Lie Lied LiedLie Lay Lain?Hang? and ?Lie? are Strong Verb as well as Weak Verb with different meanings.The picture was hungon the wall.But, the killer was hangedyesterday.Or, he lied to youBut, he lay on the floor.We should observe and study the different kinds and forms of Verbs keenly.On the basis of SubjectIt is known to us that generally a Verb has a Subject. But sometimes Verbs changing their forms cannot take any Subject and even they cannot express a complete sense i.e. they cannot form a complete Sentence. From that point of view of having or not having a Subject the Forms of Verbs are classified into two classes such as: Finite Form and Non-finite Form.The Forms of a Verb that can take a Subject are called Finite Form but the Forms of a Verb that cannot take a Subject are called Non-finite FormMost learners are informed that Verbs are of three forms like Present Form, Past Form and Past Participle Form. (Go Went Gone)I go. I went. But never I gone.The above sentences show that Present Form and Past Form must have a Subject but Past participle must not have a Subject.So only the Present Form and the Past Form of a Verb are Finite Forms. Only these two Forms can be used as a Finite Verb in a Sentence taking a Subject. And all other forms of a Verb are called Non-finite Form.Non-finite Forms cannot take any Subject and inversely it can also be said that no Subject takes or allows any Non-finite Forms of a verb after it.It should be noted here that a Verb has more than three Forms and we have to have a clear knowledge about all Forms of a Verb to earn a good command in English
For more examples: http://english.learnhub.com/lesson/12077-classification-of-verbsThanks all.