SIMPLE PRESENT
Expresses an event or situation that exists now or that usually, always or often exists.
Example: He always eats dinner at 7:30.
Water boils at 100 degrees centigrade.
SIMPLE PAST
Expresses an event or situation that began and ended in the past
Example: He ate dinner last night at 7:30.
SIMPLE FUTURE
Expresses an event or situation that will happen at one particular time in the future.
Example: He will eat dinner tomorrow night at 7:30.
THE CONTINUOUS TENSES
Give the idea that an event or situation is in process during a particular time.
Example: While he was eating, the doorbell rang.
THE PERFECT TENSES
Give the idea that one event happens or happened before another time or event.
Example: She had eaten before she arrived.