There are 12 tenses in English grammar. These tenses are used to indicate the time of an action or event. Each tense has its own unique form and use.

Present Simple Tense:
- This tense is used to express general truths, habits, and routines.

Present Continuous Tense:
- This tense is used to talk about actions happening at the moment of speaking or temporary actions.

Present Perfect Tense:
- This tense is used to talk about past actions that have a connection to the present or actions that have just been completed.

Present Perfect Continuous Tense:
- This tense is used to talk about actions that started in the past, are still ongoing, and have a connection to the present.

Past Simple Tense:
- This tense is used to talk about completed actions in the past.

Past Continuous Tense:
- This tense is used to talk about ongoing actions in the past.

Past Perfect Tense:
- This tense is used to talk about actions that happened before another past action.

Past Perfect Continuous Tense:
- This tense is used to talk about ongoing actions that started in the past and continued until another past action.

Future Simple Tense:
- This tense is used to talk about actions that will happen in the future.

Future Continuous Tense:
- This tense is used to talk about ongoing actions that will happen in the future.

Future Perfect Tense:
- This tense is used to talk about actions that will be completed before a specific time in the future.

Future Perfect Continuous Tense:
- This tense is used to talk about ongoing actions that will be completed before a specific time in the future.

These 12 tenses cover various timeframes and help in accurately conveying the time of an action or event in English grammar.