Verbs are a class of words used to show the performance of an action (do, throw, run), existence (be), possession (have), or state (know, love) of a subject. A verb shows what something or someone does.
Most statements in speech and writing have a main verb. These verbs are expressed in tenses which place everything in a point in time.
Verbs have moods, which indicate the viewpoint of the verb, whether it is a fact, a command or hypothetical. The English moods are indicative, subjunctive, and imperative.
Verbs have a voice too. The voice shows whether the subject of a sentence is carrying out an action, or is having an action carried out on it.
Verbs are conjugated (inflected) to reflect how they are used. There are two general areas in which conjugation occurs; for person and for tense.
Grammatical tense is a way languages express the time at which an event described by a sentence occurs. Tense is a grammatical category that locates a situation in time, that indicates when the situation takes place. In languages which have tense, it is usually indicated by a verb or modal, often combined with categories such as aspect, mood, and voice. In English, this is a property of a verb form, and expresses only time-related information. Viewed in the strictest linguistic sense, English has only two true tenses: nonpast tense and past tense, which are shown with the verb endings – ? and – ed.
Conjugation for tense is carried out on all verbs. All conjugations start with the infinitive form of the verb. The infinitive is simply the to form of the verb. For example, to begin. The present participle form (the -ing form), is formed by adding ing to the bare infinitive. For example, the present participle of the verb to begin is beginning. There are two other forms that the verb can take, depending on the tense type and time, the simple past form (began) and the past participle (begun). See here for a list of irregular verbs.
Conjugation for person occurs when the verb changes form, depending on whether it is governed by a first, second, or third person subject. This gives three conjugations for any verb depending on who is acting as the subject of the verb. For example, we have: to begin, you begin , and he begins. Note that only the third conjunction really shows a difference.
In English – s is plural when it appears on nouns but singular when it appears on verbs.
While most English verbs simply do not show extensive conjugation forms for person, an exception is the verb to be.
In English as in many other languages, the passive voice is the form of a transitive verb whose grammatical subject serves as the patient, receiving the action of the verb. The passive voice is typically contrasted with the active voice, which is the form of a transitive verb whose subject serves as the agent, performing the action of the verb.

Примеры.

John threw the ball. ? The ball was thrown.
John gave Mary a book. ? Mary was given a book.
I see you.
Take it.
To be a good teacher is truly an art.
He learned to swim two years ago.
Her job is to respond to customer requests.
I was confused.
The job was completed on time.
Our plan was approved by the authorities.
I cut myself shaving.
We really enjoyed ourselves.
The meeting starts at 9.
This book sells very well
The door opens from the inside.
The museum is located downtown.
This principle is difficult.
Thanksgiving is celebrated in November.
I will take out these boxes.
Fred shut down his business.
She made up that story.
I learn English now.
I learned English last year.
In a short time she has learned English well.
I drive my car every day.
English verbs are simple.
I am late.
I am driving a car.
I am being late again.
I feel pain from the injury.
I feel nervous.
My friend is a teacher.
Mike became the president of the company.
John studies English.
John studies hard.
Mother sang the song to her children.
I washed the car yesterday.
I took my sister to the movie.
John studies English.
He needs help now.
He wants a drink now.
I have a dollar now.
Nancy looks tired.
John misses Sally.
The coffee smells good.
The table weighs a lot.
The massage feels great.
I don’t feel well today.
Joe is American.
I am tasting the cake.
Debbie is missing her favorite TV program.
She is hearing voices.
She hears the music

Список литературы.

1. Bybee, Joan L., Revere Perkins, and William Pagliuca (1994) The Evolution of Grammar: Tense, Aspect, and Modality in the Languages of the World. University of Chicago Press.
2. Comrie, Bernard (1985) Tense. Cambridge University Press. [ISBN 0–521–28138–5]
3. Грамматика английского языка (на английском языке) / Под ред. В.Л. Каушанской. – 4 е изд. – Л.: Просвещение, 1973. – 319 с.
4. Грамматика современного английского языка: A new university English grammar: Учебник для студ. высш. учеб. заведений / Под ред. А.В. Зеленщикова, Е.С. Петровой. – М.; СПб.: Academia, 2003. – 640 с.