SINCE= da quando : it refers to a definite time in the past. It shows the beginning of the action

FOR = da , it refers to a period of time showing the duration of the action

Present perfect continuous: it expresses an action that began in the past, continued , and is continuing up to the present moment.

• I've been shopping (from 2.30 until this moment)
• I've been doing an English translation (since I came out of school)

When you use a present perfect continuous you are thinking of the length of time taken by one action before another in the past

The Present Perfect tense also can express an action continuing from the past to the present moment, and often either tenses can be used but with a slight difference in meaning.

• I've read a lot this week (that's what I have accomplished)
• I've been reading a lot this week (during the week, I have done a lot of reading)

When you use a present perfect you are thinking of the completion of one action before another in the past

For a long time / For long

1. She hasn't worked for a long time (and isn't working now) >> E' da molto che non lavora

Negative Present Perfect + FOR A LONG TIME

2. He hasn't been working for long (but he is still working) >> Non è da molto che lavora

Negative Present Perfect Continuous + FOR LONG

3. She hadn't worked there for a long time >> Era da molto che non lavorava lì

negative Past Perfect + FOR A LONG TIME

4. He hadn't been working there for long >> Non era da molto che lavorava lì.

Negative Past Perfect Continuous + FOR LONG

5. They haven't known each other for long >> Non è da molto che si conoscono

6. He hasn't been there for long >> Non è da molto che è lì

Verbs of perception, BE and HAVE do not usually have a progressive form with SINCE and FOR

FOR LONG cannot be used in the affirmative

Either FOR LONG and FOR A LONG TIME can be used in the interrogative

has he been working in London for a long time/for long?

EXERCISES