Tense is a fundamental concept of English grammar. Learning tenses is the first step toward mastering the English language, as they enable us to express actions clearly with reference to time of its occurrence.

A tense is the form of a verb used in a sentence to express an action with regard to the time of its occurrence. It helps indicate whether an action takes place in the past, present, or future. 

• She writes a letter. (present)
• She wrote a letter. (past)
• She will write a letter. (future)

In everyday communication, we use many sentences. Each sentence shows an action and the time at which it occurs —past, present, or future. Therefore, every sentence belongs to a specific tense.

Tenses can be defined as a set of rules for using the correct main verb and helping verb to precisely express the time of occurrence of an action.

To express the correct time of an action (present, past, or future), specific forms of verbs are used. These include both the main verb and the helping verb. Different sentence structures are formed depending on the time of the action. Thus, tenses provide the rules for using correct verbs and constructing grammatically correct sentences.

   Structure of Sentence in Tenses – How to Learn Tenses?

Tenses are mainly categorized into three types: (1) Present Tense, (2) Past Tense, and (3) Future Tense. Each of these types has four further sub-types; however, these will be discussed later to avoid confusion. For now, we know that there are a total of 12 sub-types. Each of these 12 tenses expresses a different time (or nature of time) of occurrence of an action, and each of these 12 tenses has different rules regarding the following:

• Which form of the main verb will be used (e.g., eat, write, buy, go, etc)
• Which helping or auxiliary verb will be used (e.g., is, are, was, were, have, had, will etc)
• How to form a positive sentence (e.g., subject + auxiliary + main verb + object)
• How to form a question sentence (e.g., starting the sentence with the auxiliary verb, etc.)
• How to form a negative sentence (e.g., using not after the auxiliary verb, etc.)

Let us start with what a main verb and a helping verb are in a sentence.

   Role of Verbs in Tenses

Each type of tense uses a specific form of the main verb and helping (or auxiliary) verb to form the structure of a sentence. The structure of a sentence (including the form of the main verb and helping verbs) varies for each tense because each tense represents a different time of occurrence of an action.

Therefore, a tense tells us about the following:

1. Which form of the main verb should be used?
2. Which helping verb should be used?
3. Structure of the sentence.

   Types of Tenses:

Tenses are classified into three major types:

1. Present Tense (It expresses an action that occurs in the present.)
2. Past Tense (It expresses an action that occurred in the past.)
3. Future Tense (It expresses an action that will occur in the future.)

Examples

• They worked in a factory. (Past Tense)
• They work in a factory. (Present Tense)
• They will work in a factory. (Future Tense)

The time of an action is generally divided into three major categories: past, present, and future.
However, within each main category, the nature of the action can be described more precisely. For example, an action may have occurred in the near or distant past, or it may have continued for a period of time. Based on such distinctions, each of the three major tenses is further divided into four subtypes, resulting in a total of twelve tenses.

Subtypes of Tenses

Present Tense

• Present Indefinite Tense
• Present Continuous Tense
• Present Perfect Tense
• Present Perfect Continuous Tense

Past Tense

• Past Indefinite Tense
• Past Continuous Tense
• Past Perfect Tense
• Past Perfect Continuous Tense

Future Tense

• Future Indefinite Tense
• Future Continuous Tense
• Future Perfect Tense
• Future Perfect Continuous Tense

As noted above, each of the three main tenses is further divided into four subtypes. These subtypes describe not only when an action occurs but also how it occurs—whether it is simple, ongoing, completed, or continuing over a period of time.

Present Tense

• Present Indefinite Tense – expresses general facts, habits, or routine actions.
  Example: She writes a letter.
• Present Continuous Tense – expresses actions that are happening at the moment of speaking.
  Example: She is writing a letter.
• Present Perfect Tense – expresses actions that have been completed at an unspecified time before now.
  Example: She has written a letter.
• Present Perfect Continuous Tense – expresses actions that started in the past and are still continuing.
  Example: She has been writing a letter.

Past Tense

• Past Indefinite Tense – expresses actions that were completed in the past.
  Example: She wrote a letter.
• Past Continuous Tense – expresses actions that were ongoing at a specific time in the past.
  Example: She was writing a letter.
• Past Perfect Tense – expresses actions that were completed before another action in the past.
  Example: She had written a letter.
• Past Perfect Continuous Tense – expresses actions that continued for some time before a certain point in the past.
  Example: She had been writing a letter.

Future Tense

• Future Indefinite Tense – expresses actions that will happen in the future.
  Example: She will write a letter.
• Future Continuous Tense – expresses actions that will be ongoing at a specific time in the future.
  Example: She will be writing a letter.
• Future Perfect Tense – expresses actions that will be completed before a certain time in the future.
  Example: She will have written a letter.
• Future Perfect Continuous Tense – expresses actions that will continue for a period of time before a specific point in the future.
  Example: She will have been writing a letter.

To study each type of tense in detail, including its rules and examples, click the following links: