Present perfect continuous

Present continuous for unfinished actions
Have/Has been + Verb+ing
Use the present perfect continuous with for and since with action verbs.
How long have you been learning Spanish?
He's been studying here since September.
They've been going out together for four years.

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With non-action verbs (know, be, etc.) use the present perfect simple, NOT the present perfect continuous. with for and since. I've known her for ages. NOT I've been knowing her for ages.
With live and work you can use the present perfect simple or continuous with for and since. I've been living here for six months. I've lived here for six months.

Present perfect continuous for recent continuous actions
Use the present perfect continuous for actions which have been going on very recently. They have usually just stopped.
Your eyes are red. Have you been crying? No, I've been cutting onion.