I think you should probably know the difference between tense, aspect & mood.
1-Tense is the correspondence between the form of the verb and our concept of time.
--> Tense= Present + Past
2-Aspect concerns the manner in which the verb or action is experienced or regarded as complete or in progress.
e.g.
She is trying to help me.
(present progressive --> progressive aspect: expressing an action in progress)
We have studied this before.
(perfect aspect --> expressing an action not completed)
3-Mood relaxes the verbal action to such conditions as certainty, permission etc ...
It tells us what the speaker thinks or is thinking about.
e.g.
You must obey your parents! (obligation)
It may rain this evening. (possibility)
NB
-The future is an unreal tense.
-Aspect= simple / complex:
perfective
progressive
perfect progressive
-Mood= reflects:
obligation
permission
possibility
probability
acceptance - refusal - invitation etc ....
-There are two types of stative verbs:
Current, showing some state.
and
Resulting stative verbs, in which, the result is shown in the verb itself.
e.g.
Such a theory has become clear.
The soil gets wet.