There are only three verb tenses in English grammar: Past, Present, and Future. Each of these has four aspects: Simple, Continuous (or Progressive), Perfect, and Perfect Continuous. This makes a total of 12 ordinary tenses.

The following is each tense's rule and example:

1. Present Tenses

1.1. Present Simple (or Simple Present)

• Rule:  Base form of the verb. Append '-s' or '-es' for third-person singular subjects (he, she, it).
  • Formula: Subject + V1 (base form) / V1 + s/es (for he/she/it)
• Uses:
  • To describe habits or repeated actions.
    • Example: She drinks tea every morning.
  • To declare general truths or facts.
    • Example: Water freezes at zero degrees Celsius.

• • For fixed schedules or arrangements (most commonly for future events).
    • Example: The train leaves at 7:00 PM.

• • To provide instructions or directions.
    • Example: You turn right at the corner.

• Examples:
  • I walk to school.
  • He plays football.
  • They study English.

1.2. Present Continuous (or Present Progressive)

• Rule:Present tense of "to be" (am, is, are) + present participle (-ing form) of the main verb.
• Formula:Subject + am/is/are + V-ing
• Uses:
  • To tell what is happening at the time of speaking.
    • Example: I am writing an email right now.
  • In order to talk about things that are occurring around the current moment, although not necessarily at the actual time.
    • Example: She is preparing for her exams this week.
  • For arranged future situations (scheduled appointments).
    • Example: We are having dinner with them tomorrow night.
  • In order to talk about temporary circumstances.
    • Example: He is staying with his aunt this month.
  • With "always," "constantly," "forever" to talk about repetitive, frequently annoying behaviors.
    • Example: You are always grumbling!
• Examples:
  • She is singing.
  • They are playing in the park.
  • I am reading a book.

1.3. Present Perfect

• Rule:"Have" or "has" + past participle (V3) of the main verb.
• Formula:Subject + have/has + V3
• Uses:
  • To describe actions which occurred at some time in the past, but have a bearing on the present.
    • Example: I have visited Paris twice. (The experience is relevant now)
  • In order to explain actions that began in the past and extend to the present time.
    • Example: She has lived in London for five years.
  • For recent actions, usually with "just."
    • Example: He has just finished his homework.
  • To discuss experiences up to the current point.
    • Example: Have you ever eaten sushi?
• Examples:
  • They have seen that movie.
  • She has begun a new job.
  • I have lost my keys.

1.4. Present Perfect Continuous (or Present Perfect Progressive)

• Rule:"Have been" or "has been" + present participle (-ing form) of the main verb.
• Formula:Subject + have/has + been + V-ing
• Uses:
  • To describe actions that began in the past and continued up to the present moment. The focus is on the length of time.
    • Example: She has been studying for three hours.
  • To state actions which have recently concluded, but their results are apparent or still applicable in the current time.
    • Example: I'm exhausted since I have been running.
• Examples:
  • It rained throughout the morning.
  • They waited for you for one hour.
  • He has been working on this project since last month.

2. Past Tenses

2.1. Past Simple (or Simple Past)

• Rule:For regular verbs, append '-ed' to the base form. For irregular verbs, append their own past tense form.
• Formula:Subject + V2 (past form)
• Uses:
  • To describe completed actions or events that occurred at a particular moment in the past.
    • Example: I went to the store yesterday.
  • To describe a chain of completed actions in the past.
    • Example: She woke up, ate breakfast, and left for work.
  • To refer to habits or routines in the past.
    • Example: As a child, I played outside daily.
• Examples:
  • He watched a movie last night.
  • They completed their work.
  • She resided in Japan.

2.2. Past Continuous (or Past Progressive)

• Rule:"Was" or "were" + present participle (-ing form) of the main verb.
• Formula:Subject + was/were + V-ing
• Uses:
  • To state an action which was ongoing at some point in the past.
    • Example: I was having dinner at 8 PM last night.
  • To state an action which was still ongoing in the past but was interrupted by some action.
    • Example: I was reading when the phone rang.
  • To state two or more actions occurring simultaneously in the past.
    • Example: My brother was watching television while I was cooking.
  • To define the background environment in a narrative.
    • Example: The sun was shining and birds were singing.
• Examples:
  • She was studying when I phoned.
  • They were playing basketball.
  • It snowed all day yesterday.

2.3. Past Perfect

• Rule:"Had* + past participle (V3) of the main verb.
• Formula:Subject + had + V3
• Uses:
  • To explain an action that was finished before another action in the past. It makes the order of events clear.
    • Example: By the time I arrived, she had already left. (First she left, then I arrived).
  • To express a cause-and-effect relationship in the past.
    • Example: He was tired because he had worked all night.
  • In reported speech.
    • Example: She said she had seen him before.
• Examples:
  • I had eaten dinner before they arrived.
  • They had finished the project by Friday.
  • She had never seen such a beautiful sunset before that day.

2.4. Past Perfect Continuous (or Past Perfect Progressive)

• Rule:"Had been" + present participle (-ing form) of the main verb.
• Formula:Subject + had + been + V-ing
• Uses:
  • To talk about an action that was being done for some amount of time in the past, up to some other definite point in the past.
    • Example: She had been waiting for two hours before the bus finally arrived.
  • To describe the cause of a past event.
    • E.g.: His eyes were red because he had been crying.
• Examples:
  • They had been living there for ten years when they made the decision to move.
  • I had been learning English for five years before I moved to England.
  • He had been running, so he was short of breath.

3. Future Tenses

3.1. Future Simple (or Simple Future)

• Rule:"Will" + base form of the main verb. (Also, "be going to" + base form is standard for future plans/predictions).
• Formula:Subject + will + V1
• Alternative:Subject + am/is/are + going to + V1
• Anticipated uses:
  • For predictions about the future.
    • Example: It will rain tomorrow.
  • For spontaneous decisions or offers.
    • Example: I will help you with that.
  • For promises or intentions.
    • Example: I will call you later.
  • For future facts.
    • Example: The sun will be rising at 6 AM.
  • "Be going to" is usually employed in making arrangements or intentions, or in making predictions on the basis of current evidence.
    • Example: I am going to see my grandmother next week. (Arrangement)
    • Example: Look at clouds; it's going to rain. (Prediction based on evidence)
• Examples:
  • She will be traveling next year.
  • They are going to construct a new house.
  • I will be seeing you soon.

3.2. Future Continuous (or Future Progressive)

• Rule:"Will be" + present participle (-ing form) of the main verb.
• Formula:Subject + will be + V-ing
• Uses:
  • To describe an action that will be going on at a particular point in the future.
    • Example: At 10 AM tomorrow, I will be working.
  • To describe an action that will be in progress when another future action is taking place.
    • Example: When you arrive, I will be cooking dinner.
  • To inquire politely about the plans of someone.
    • Example: Will you attend the party this evening?
• Examples:
  • He will be studying throughout the evening.
  • They will have dinner upon our arrival.
  • I will be waiting for you at the station.

3.3. Future Perfect

• Rule:"Will have" + the past participle (V3) of the main verb.
• Formula:Subject + will have + V3
• Uses:
  • To indicate an action to be finished prior to a point in the future.
    • Example: I will have graduated from university by next year.
  • To convey an assumption regarding something already done.
    • Example: He will have come by now.
• Examples:
  • She will have completed her report by 5 PM.
  • They will have constructed the bridge by 2030.
  • I will have read this book by the end of the week.

3.4. Future Perfect Continuous (or Future Perfect Progressive)

• Rule:"Will have been" + present participle (-ing form) of the main verb.
• Formula:Subject + will have been + V-ing
• Uses:
  • To express an action that will have been in progress for a specific period up to some time in the future. The stress is placed on the period leading up to that future time.
    • Example: In November, I will have worked for five years at this company.
  • To indicate the cause of an event in the future.
    • Example: After he completes his marathon, he will have been running for four hours.
• Examples:
  • By the time she goes to bed at midnight, she will have slept for six hours.
  • They will have been on the road for 24 hours when they arrive at their destination.
  • I will have been waiting for him for an hour when he finally arrives.

Understanding these tenses and their applications is crucial for effective communication in English.