In the negative form the negative particle not is placed after the auxiliary verb.

The use of The Present Perfect Continuous

The Present Perfect Continuous is used to denote:

1. An action which began in the past, has been going on up to the present moment and is still going on(The Present Perfect Continuous Inclusive).It’s generally used with since, for, these 2,3 .. days, etc.

Ever since I saw you last I have been thinking, thinking.

2. Can be used with certain non-terminative verbs.

We have been working and working at the problem for months and I don’t think we are likely to solve it.

3. A) An action which was recently in progress but is no longer going on at the present moment(The Present Perfect Continuous Exclusive).

You look distressed. You have been weeping.

B) To express repeated actions in the past.

How long have you been spending your money?

C) Is often used with an emotional colouring.

I suppose you have been telling lies again.

The Past Perfect Continuous

The Past Perfect Continuous is formed by means of the Past perfect of the auxiliary verb to be and Participle I of the notional verb.

In the interrogative form the auxiliary verb is placed before the subject.

In the negative form the negative particle not is placed after the auxiliary verb.

The use of the Past Perfect Continuous

The Past Perfect Continuous is used to denote:

1. An action which began before a definite moment in the past, continued up to that moment and was still going on at that moment (the Past Perfect Continuous Inclusive).

We could not go out because it had been raining since early morning.

2. Can be used with certain non-terminative verbs.

He said he had been working for a long time without achieving final results.

3. An action which was no longer going on a definite moment in the past, but which had been in progress not long before(the Past Perfect Continuous Exclusive).

I sobbed a little still, but that was because I had been crying.