The first excerpt is:
- A man ner the window is looking at us. - Yeah, and what of it? - I've been meeting him at the library lately.
In this case "lately" inmplies the process of meeting as a repeated and continuos action which started at some moment in the past and is continuing up to the present time. Do I use it correctly? Certainly, I've learnt Present Perfect and Present Perfect Progressive are closely related except for "some duration" in the second case and "making emphasises on number" in the first. I don't say it is awkward enough to me but nevertheless. Unfortunately it's hard to explain. May be I should had used Present Perfect?
Although, there is no actual difference between them as we could use them instead one another without any distinction in the meaning.
I've just deleted one of my topics to in order to improve it and make it clearer.
- I've been developing photos for the whole day.
Someone said I should had written it as:
- I've been developing photos all day.
I hav got some experience practicing exercises and know we use "for" and "since" with Perfect Forms. Since we talk about some period from starting point we should use it. But actually I'm not a native so it's too difficult for me to state it with no doubt that this adverb is used in a right manner at all.