Present Perfect I

The present perfect tenses of verbs, simple and continuous, are formed as follows:

AFFIRMATIVE	NEGATIVE		INTERROGATIVE
Present Perfect Simple
	Long Form	Contracted Form
I have done	I have not done	I haven't done	Have I done?
You have done	You have not done	You haven't done	Have you done?
He/she/it has done	He/she/it has not done	He/she/it hasn't done	Has he/she/it done?
We have done	We have not done	We haven't done	Have we done ?
You have done	You have not done	You haven't done	Have you done?
They have done	They have not done	They haven't done	Have they done?

AFFIRMATIVE	NEGATIVE		INTERROGATIVE
Present Perfect Continuous
	Long Form	Contracted Form
I have been doing	I have not been doing	I haven't been doing	Have I been doing?
You have been doing	You have not been doing	You haven't been doing	Have you been doing?
He/she/it has been doing	He/she/it has not been doing	He/she/it hasn't been doing	Has he/she/it been doing?
We have been doing	We have not been doing	We haven't been doing	Have we been doing ?
You have been doing	You have not been doing	You haven't been doing	Have you been doing?
They have been doing	They have not been doing	They haven't been doing	Have they been doing?

The present perfect is used to refer to actions which take place in an unfinished time period up to the time of speaking.

The present perfect continuous tense is used to refer to an action which started in the past and continues today. It emphasises the uninterrupted progress of an action.
- I have been learning English since September.
  (I started in September and I continue to take lessons today.)
The present perfect simple is used to refer to the finished part of a continuous action.
It emphasises the completion of an action and its results.

So far in my English course:
- I have learnt new vocabulary.
- I have revised some grammar rules.
(My English course is not finished, but I have finished some of the lessons.)

Example:
Today is your English Revision day. It is now 2 p.m.
At 9 o'clock this morning you started your revision work. At 2 pm the day is not finished, so you can say :
"I have been revising my English since 9 o'clock this morning."
(You are still revising your English, so the continuous form is used.)

However, you have completed part of the revision work, so you can say, for example:
"So far today I have revised tenses and irregular verbs."

N.B.
If you refer to a specific time earlier in the day, you must use the Past Simple :
"This morning I revised tenses and irregular verbs."
"Charlie called me at 10h30."
"I hada sandwich at lunch time"

The following should be noted:

1) Some verbs can be used in both forms with no change in meaning.

With some verbs such as live and work, the present perfect simple OR continuous can generally be used with no difference in meaning.

I've lived/I've worked here for 10 years.
I've been living/I've been working here for 10 years.

However, only the present perfect simple is used with 'always'.

I've always lived here NOT I've always been living here.

2) Stative Verbs

Stative verbs have no continuous form.
Stative verbs are verbs that denote possession, mental states or emotions,
for example: own, belong, know, believe, like, wish ...
We can say: "I’ve known Bob for 20 years" NOT "I have been knowing Bob for 20 years".

Present Perfect Tense

(example : to do)