If I see a friend with a lot of shopping bags and I want to inquire in a friendly way what they have bought, should I ask: what have you bought? or what have you been buying? Are both possible without any difference in meaning? If I want to know if my husband has ordered something that has been delivered and I want to ask in a neutral way could I ask "have you ordered something?" or "have you been ordering something?" without difference? I am wondering if the continuous conveys some sort of negativity ( annoyance or accusation )in these cases.
My feeling is that when you say "I have been doing something.", it means that right up to the moment you started saying the sentence, you have been doing that thing.
When you say "I have done something useful.", it means that you were working on it for a while in the past and finished it at some point near the present.
I have done it! I did it!I have been doing it!
"I have done it" describes the whole process of you spending the time and doing something that is already finished.
"I did it" describes the point in time that you finished it.
"I have been doing it" describes the process of you doing something up till now that isn't done yet.
First of all, you need to understand the difference between them.
Task which completed in the near past (recently) are considered as present perfect.
Example: What have you bought? You are asking him which points one of his task for this time.
Ex: I have gone to school. Means it's represent for today
Present perfect continues
Task which occurs repeatedly in a certain time or interval of time, which happened in past at least once + happened in the near past (recently) + will happen in the future.
Example: What have you been buying? You are asking him 3 questions here which points 3 actions. Means you are asking him whether bought before and whether bought now and whether also will bought tomorrow or in future
Ex: I have been going to school Means i used to go to school. Yesterday, today and tomorrow. It's a continuous task. That's why it is known as perfect continuous.