- American speakers tend to use the present perfect much less than British speakers.
- Lately I get the feeling that... is just idiomatic AmE. It's not the same as, say, Lately I've been feeling sick ..., which is normal AmE: it's present perfect progressive because it's a consistent feeling. I use the present perfect much more than most AmE speakers, but I wouldn't say Lately I've had the feeling that... unless I didn't have it at the moment of speaking. Lately I've got the feeling... doesn't feel like AmE to me.
- ... have you noticed how much more time Paul has {spent/been spending}...? is idiomatic AmE, but I suspect that a lot of AmE speakers would say it in simple past: ... did you notice how much more time Paul {spends / has spent / has been spending}...?
The sequence of tenses is difficult for all speakers, native speakers included. What each tense, aspect, mood, voice, etc. is used for is a mystery to most. We just instinctively say what we say and use whatever tense seems to fit. IOW, I don't think it's possible to provide a rule-governed explanation of why people use one tense instead of another.
I agree with Reg Dwight that "there is no rule that 'lately invites the Present Perfect'." I'd say "Lately I feel sad about how vitriolic American politics has become" as soon as I'd say "Lately I've {felt / been feeling} sad about how vitriolic American politics has become". It'd all depend on whether I was feeling sad at the moment or whether I'd been riding a roller coaster of sadness and indifference.
When 'recently' or 'lately' is used with present perfect progressive:
Since the adverbs recently and lately both suggest that something is done either "at a recent time" or "not long ago", using these words to describe a particular ongoing action in the past does not necessarily imply that the action is continuing right up to the present.
Scenario 1: A is having lunch with B.
A: Have you been listening to the podcasts by Brain Cox recently/lately?
B: Yes. (But this does not imply that the action is continuing right up to the present.)
When 'recently' or 'lately' is not used with present perfect progressive:
Omissions of adverbs such as recently and lately do not necessarily suggest that an action is complete.
Scenario 2: A saw B sitting on a bench.
A: How long have you been sitting on the bench?
B: A couple of minutes.
What about the present perfect?
The present perfect is normally used to denote the present state of an action's being completed, that is, that the action took place before the present time.
Habitual action:
The present perfect and the present perfect progressive can both be used to talk about an action that is habitual:
"I have gone out with her every weekend."
"I have been going out with her every weekend."
Using the present perfect progressive can imply that this habitual action is continuing right up to the present, but it may not always be the case.
Updates: When 'recently' or 'lately' is used with present perfect progressive
Describing an action in the present perfect progressive form with "recently" or "lately" does not necessarily imply that the action is continuing right up to the present, but it may suggest that it is a habitual action.
"I've been going to the pub recently."
Describing an action in the present perfect form does not suggest that it is a habitual action.
"I've gone to the pub recently."
Best Answer
I'd like to compare the present perfect usage with the simple past one.
First, the simple past.
All three sentences are asking the same thing, the speaker would like to know when did the two people last see each other. Specifically, he's asking for a point in time.
The respondent could reply like this:
The act of seeing the woman is a finished event, completed at a specific time. That episode cannot be repeated and we know exactly when this event occurred. This tense is usually referred to as the simple past.
Alternatively...
The speaker wants to know how much time has elapsed since their last meeting. In other words, the act of not seeing each other. The action of not seeing somebody is a continuous one, it began in the past and continues to the present. The two people have not seen each other since 1993 or if you prefer, for twenty years.
Therefore, the present perfect tense is the most acceptable one in this type of situation, and the most recommended (without any contractions) for formal writing.
In spoken English; however, it is common to use this type of construction
it is + period + since + past or perfect tense.
The meaning is the same as the present perfect sentences above.
http://www.grammaring.com/its-been-days-weeks-months-etc-since