您好，这3个时态的区分在于：
1）Simple Past（一般过去时）：动作发生在过去，也在说话之前结束了，强调状态，和时间点，也就是发生了没，和现在没有关联。
2）Present Perfect（现在完成时）：动作开始于过去，在说话时可能刚结束，也可能没有结束，要是刚结束，对说话时产生影响；要是没有结束，会持续到将来，对将来产生影响；可以强调时间点，也可以强调时间段的影响。
3）Present Perfect Progressive（现在完成进行时）：和（现在完成时）一样，但说话时尚未结束，确定会持续到将来某个时间点，影响在将来。当是否持续不确定时，（现在完成时）和（现在完成进行时）可以互换。
High school students Sydney Martin (has always loved) rocks, and several years ago, she (has found) the perfect way to use her rock collection. Sydney's rocks come from the Lake Michigan beaches near her home. She (has been using) them to make necklaces since she (was) eight years old. In 2005, Sydney (sold) her first necklaces to family and friends and put the money in the bank. Two years later, when doctors (told) Sydney that she had LCH, she immediately (knew) what to do with the profits from her jewelry. She (decided) to give the money to doctors trying to find a cure for LCH and she (hasn't stopped) since. Syndey (has started) a business, Syd Rocks, to sell her rock jewelry. So far, she (has donated) more than $420,000. Sydney's motivation is simple. She wants to help in the fight against LCH.
现在完成时：强调过去发生或已经完成的某一动作对现在造成的影响或结果。不能有表示过去的时间状语。He has worked there for five years. （他已经在那儿工作了五年。）时间状语有for+一段时间，since+时间点
现在完成进行时：强调动作由过去一直持续到现在，而且还要持续下去。He has been working there for five years.(他已经在那儿工作了五年。还要一直干下去）
如果表示动作发生在过去，但对现在会产生一定的影响，则用现在完成时。
如果表示从过去开始一个动作，到现在仍然在持续，我们会用现在完成进行时，即助动词have或has加be的过去分词been再加现在分词构成。
