As i see that.. Past Simple is for the most situations you will have. Like storytelling. Past Perfect is pretty exotic thing. What do you think?

Continuing from my previous answer ‘I posted them a few minutes ago’ or ‘I posted them earlier’. The action is completed. ‘I have posted them’ doesn’t give any information about when this happened, so uses present perfect. As soon as you say that time has passed since you did it, you use simple past. Note, however, that if the event is very recent, you continue to use the present perfect : ‘I have just posted them’. You will hear people say ‘I just posted them’ [simple past] but it doesn’t sound quite right to me. This would be a good topic for an Italki discussion where you can get expert opinion from people like Phil. Possibly for very recent events either present perfect or simple past are acceptable. ‘They’ve just done it’ ; ‘They just did it’. I prefer the first, but the second is also commonly heard. ‘I’ve just been there’ ; ‘I just went there’. The past perfect also gets confused with the simple past but, if you like [to think of it this way], in the other direction. When you are referring to two or more events in the past, which happened at different times, you use the past perfect to put them in chronological [time] order. ‘I had been learning Chinese for some time when I realised I couldn’t make myself understood when I spoke.’ The learning period preceded [came before] the realisation that I was not understood, so ‘I had been learning . . ‘ or ‘I had learned. . ‘ is in the past perfect. ‘I was not understood’ and ‘I spoke’ are in the simple past. The sentence could be written the other way around : ‘I couldn’t be understood when I spoke although I had been learning Chinese for some time.’ Native speakers use these tenses intuitively without having to think about it, and I understand how difficult it is for learners of English to work out which to use. I have noticed, however, that even [presumably native] English speakers do make mistakes in this, so I don’t think you should worry about doing that.

Another attempt to explain these tenses that I made recently for someone else. I have split it in to parts to allow me to post it. Present perfect is used to make statements or ask questions about something that started in the past [usually the recent past, but not necessarily], and may either still be happening, or has stopped but is directly linked to something to which you have been referring. The best way to understand this is through seeing how it is used in practice, and I will try to give you some examples. ‘How long have you been learning Chinese ?’ [present perfect continuous] OR ‘For how long have you learned Chinese ?’ [present perfect] The question is asked on the understanding that the person concerned is still learning Chinese. ‘For how long did you learn Chinese ?’ OR ‘For how long were you learning Chinese ?’ [simple past / past continuous] when the person is no longer learning Chinese. ‘I learned Chinese when I was a student at university.’ simple past : (s)he is no longer learning Chinese. ‘I started learning Chinese when I was a student at university.’ simple past - ‘I started. . ‘ - I am not now still starting, though I may still be learning Chinese. ‘Have you been to China ?’ [present perfect] The question is asked because it is relevant to the current discussion, even though the event [going to China] is in the past, possibly the distant past. ‘Yes, I went to China last year’ - simple past - event finished ‘Yes, I have been to China’ - present perfect - note that the time you went has not been stated, so leaves open the prospect of a follow-up statement by yourself or another question ‘When was that ?’ The event [going to China] is in the present perfect as no statement has yet been made that puts it in the past. When you reply to the follow-up question ‘When was that ?’, the response will be in the past ‘I went last year’ ; ‘It was five years ago’.

I tried to give an example of the use of these tenses to someone recently. “The events described occurred in the past and are now finished, so simple past ‘kept’. If we were to write ‘. . has kept nutria in check for decades’ it would mean that it has only recently ceased to do that [i e. stopped doing that]. In that case the sentence would read something like : ‘The fur trade has kept nutria in check for decades, but now that the market for nutria has collapsed, the cat-sized animals have multiplied like crazy.’ The whole sentence is written in the present perfect, as the situation is current i e. applies now, in the present. A period of time can apply to both the completed past, in which case you would use the simple past tense, or the recent past, maybe up to the present, when the present perfect will be used. It is possible to use the past perfect for completed events : ‘The fur trade had kept nutria in check for decades, but when the market for nutria collapsed in the late 1980s, the cat-sized animals multiplied like crazy.’ This would be the most correct way of writing it, as the ‘keeping in check’ precedes [happens before] the collapse of the market.”