Verb tense [The continuous (progressive)]

Verbs are words that express action (run) or a state of being (love). The action can also be
abstract rather than visible, such as the words think and decide.
Verb tense tells when an action occurred on a time line. There are three tense-
present, past, and future.
Aspect indicates whether an action is complete or not.
The simple aspect indicates that an action occurred, without an indication of when it occurred.
The continuous (progressive) aspect indicates that the action is ongoing.
These two concepts are combined to give the twelve verb 12 different verb tenses. These are:
The simple tenses- present, past, and future
The continuous tenses- present, past, and future
The perfect tenses- present, past, and future
The perfect continuous- present past, and future.

Present Perfect Continuous Tense

The present perfect continuous is formed by using: have/has + been + verb + ing ending.

Use the present perfect continuous tense:

1. When talking about events, situations, or actions that started in the past and continue

      into the present or future.
          We have been living in France for over a year.

2. When talking about how long you have done something.
          Robert has been working on that report for six weeks.

3. When talking about repeated events, situations, or actions that started in the past
      and continue to the present.
          I have been playing a lot of tennis lately.

4. When the focus of the sentence is more on the duration of the event, situation, or action
      than the result of it.
          I feel exhausted because I’ve been working all day.

Past Perfect Continuous Tense

The past perfect continuous is formed by using: had + been + verb + “ing”.
Use the past perfect continuous tense:
1. When talking about the duration of an action up to a certain time in the past.
          By the time I arrived in Seoul, it had been raining for 3 days.
2. When talking about the duration of an action before another past action.
          Robert had been studying for 30 minutes before he fell asleep.

Future Perfect Continuous Tense

The future perfect continuous is formed by using: will + have + been + verb + “ing”.

Use the future perfect continuous tense:
1. When talking about the duration of an event, action, or situation up to a certain time
      in the future.
          By December, 2009 she will have been working for the company for 12 years.
2. When talking about the duration of an event, action, or situation before another event
      in the future.
          I will have been studying for 2 hours by the time the movie ends.
Sometimes the future perfect continuous and the future perfect can be used to express
the same meaning.
When Professor Ahmad retires he will have taught for 19 years.
OR
When Professor Ahmad retires, he will have been teaching for 19 years.