The present perfect continuous tense is used to talk about things that started in the past and continue to happen up to the present at the moment of speaking. You will use this tense when your focus is on how long things happen from some point in the past to the present. When you say “I have been living in this city for a month” that means you STARTED to live in this city a MONTH AGO, and you ARE still LIVING here when you say it. In this case, FOR and SINCE are used.
THE PRESENT PERFECT CONTINUOUS TENSE VS THE PRESENT PERFECT TENSE
With some verbs such as live, work, study, we can use either the present perfect continuous tense or the present perfect tense to talk about things that started in the past and continue to happen up to the present.
I have lived in this city for a month
I have been living in this city for a month
Both sentences are correct, although we normally prefer to use the present perfect continuous tense.
Maria has worked for the electronics company since last year.
Maria has been working for the electronics company since last year.
Both sentences are correct, although we normally prefer to use the present perfect continuous tense.
However, we should note the difference between the two tenses. Compare these two sentences:
Pardi has been walking along the street for hours –> Pardi started to walk hours ago, and is still walking now. The focus is on the duration or how long something has happened until now.
Pardi has walked tens of miles along the street –> Pardi started to walk sometime ago in the past, and is or is not finished yet now. The focus is on how many miles he has walked until now.
Now compare these two sentences:
Pardi has been reading a novel for 3 hours –> Pardi started to read a novel 3 hours ago, and is still reading it now.
Pardi has read three novels so far –> the focus is on how many novels he has read until now.