Sentence

A sentence is a group of words that expresses a complete meaning, thought or idea.

Example.
I am eating an apple.

The above combination of words gives us a complete meaning or idea. Such a meaningful group of words is called a sentence.

Now, see the following group of words.

Eat saw book an hour doctor.

The above group of words cannot be called a sentence because it (as a whole) does not convey a complete meaning to the reader. Even though each word has meaning individually, the group does not convey a complete idea.

   Components of a Sentence

A complete sentence usually has:

1. Subject: The doer of the action or which acts.
2. Verb: The action.
3. Object: The receiver of the action or which is acted upon.

He eats an apple.

• He → Subject (does the action)
• writes → Verb (action)
• letter → Object (receives the action or is acted upon)

In the above example, ‘He’ is the subject because "he" does some work (i.e., eating). The word, ‘apple’ is the object because some work is being done on it (i.e., it is being eaten). The word 'write' is a verb because it give us the actual meaning if the action (i.e., to eat: to chew and swallow something).

   Other Elements in a Sentence

Sentences may also include:

• Auxiliary (Helping) Verbs: is, was, has, had, will
• Prepositions: on, at, to
• Articles: a, an, the
• Conjunctions: and, but

These elements support the main structure of the sentence and add clarity.

   Rules of Sentence Structure

• Capitalization: Always start a sentence with a capital letter.
• Punctuation: End with a full stop (.), question mark (?), or exclamation mark (!).
• Word Order: Words must be in proper sequence to make sense.

   Tenses in Sentences

Tenses in English Grammar provide the rules for using correct form of main verb and helping verb according to the exact time of the action such as past, present, or future.

• Main verbs express the basic meaning of an action (e.g., eat, write, buy). These verbs have three forms: Base (1st form), Past (2nd form), Past Participle (3rd form).
• Helping verbs do not express the basic action themselves but are used with the main verb to indicate tense (e.g., is, are, was, has, had, will). They help indicate the correct time of occurrence.

Examples.

• He had written a letter. (action occurred in past)
• He is writing a letter.    (action is occurring in present)
• He will write a letter.    (action will occur in future)

It is very much important to learning Tenses in order to form the correct structure of sentence using the correct form of main verb and helping verb according the time of an action.

   Active and Passive Voice

Active and Passive Voice is another important part of English grammar regarding the correct structure of a sentence. The action of a subject in relation to an object is expressed in two ways:

1. Active Voice: Subject performs the action.
• Example: He writes a letter.
2. Passive Voice: Object is emphasized. The object of the action becomes the focus.  
• Example: A letter is written by him.

Active voice is the common style of expression, which is frequently used in our daily routine, in which, a sentence starts with the ‘subject’ and ends with the ‘object’. e.g., He writes a letter. However, in passive voice, the places of subject and object are interchanged, e.g., A letter is written by him. Though the structure of the sentence is changed in active voice and passive voice, its basic meaning remains the same.

Using passive voice is generally preferred in a situation where it is intended to emphasize the object rather than the subject, e.g. The thief was caught by the police. Passive voice is aso used in situations where the subject is generally known and not intended to be mentioned, e.g. Sugar is sold in kilograms. Active voice is converted into passive voice according to its rule. For instance, only 3rd form of a verb (e.g., written, eaten) is used in passive voice. Similarly, the helping verb is used according to the tense of the sentence in its active voice form.

Example.

• Active voice: He eats an apple.
• Passive voice: An apple is eaten by him.

   Direct and Indirect Speech

Direct and indirect speech is also important part of English grammar regarding the structure of a sentence. These are two ways for conveying spoken-words (or message) of one person to another person. For instance, you meet your teacher (named John) at your college and he says to you ‘I want to meet your parents’. When you come home, you can this to your parents in the following two ways.

• Direct speech: John said, “I want to meet your parents”.
• Indirect speech: John said that he wanted to meet my parent.

It can be seen in the above example that in direct speech, the actual-spoken words (with no change in them) of a person are conveyed to another person. However, in the indirect speech, the words are slightly changed such as verbs and prepositions are changed. Since the actual spoken-words of a person are quoted in the direct speech, these words are enclosed in inverted commas or quotation marks.

Here are some basic examples of sentences:

 She is singing a song.
 He is a doctor.
 Kids are playing in the garden.
 He will come here tomorrow.
 We watched a movie.
 What is your name?
 It has been raining since 3 O’clock.
 I am learning how to drive a car.
 She wrote him a letter.
 They bought a new computer.
 There are ten students in the classroom.
 Where had you gone the last night?
 The birds are flying in the sky.
 He got admission in a new school.