Tense expresses when in time--past, present, or future--the actiom or state of being conveyed by a given verb takes place, and is indicated by the form of the verb used.  Verb tense can be either simple or perfect.

The Simple Tenses

        A simple present tense verb conveys what is happening or what is true right now.
 

Regular Verb	Irregular Verb	Progressive Form
I talk.	I eat.	I am talking. I am eating.

        A simple past tenseverb indicates the completion of an action or the end of a condition.
 

Regular Verb	Irregular Verb	Progressive Form
I talked.	I ate.	I was talking. I was eating.

        A simple future tense verb indicates a condition that will be true or an action that will take place in the future.
 

Regular Verb	Irregular Verb	Progressive Form
I will talk.	I will eat.	I will be talking. I will be eating.

The Perfect Tenses

        As is true with the simple tenses, the perfect tenses are also used to express time, and generally indicate the
        completion of actions or occurances that have already been completed or that will be completed
        before a given point in time.

        The present perfect tense indicates that an action has begun or has been completed in the past, but
        that it, or at least its effects, continue into the present.
 

Regular Verb	Irregular Verb	Progressive Form
I have talked.	I have eaten.	I have been talking. I have been eating.

        The past perfect tense indicates that an action was completed before another one took place.  When two actions
        both started and stopped in the past, the earlier action uses had as a helper.
 

Regular Verb	Irregular Verb	Progressive Form
I had talked.	I had eaten.	I had been talking. I had been eating.

        The future perfect tense indicates that an action will be complete before some specified or predictable time.
 

Regular Verb	Irregular Verb	Progressive Form
I will have talked.	I will have eaten.	I will have been talking. I will have been eating.