Tenses

Describes an action going on now (at the moment).

Describes an action in progress at a certain time in the past.

Declares general, universal, and true statements.
Describes the regular/permanent features of one's life, non-action or habitual action, routine.
Describes an event which depends on a fixed timeable.
Describes states.

describes action which began and ended before the present.
used for action completed in the past.
already happened in the past.

Describes an action which will happen in the future.

Describes on going action and is continuing in the future.

describes action completed at an indefinite time in the past.
describes a habitual act.

describes a past event that occurred before another past event.
action A happened before and separate from action B

describes action that will be completed in a specified time in the future.

describes an action which began but did not finish yet, action is still going on.