Which Past Tense to use present perfect(现在完成时) present perfect progressive(现在完成进行时) 1️⃣Rule: The tense doesn't really matter to the story, so we might use "present perfect" or we might use "past simple". They are interchangebly when it doesn't really matter to the story. Here are some scenarios for 1st rule. 📕Examples for"present perfect" Ex: I've talked to her,and she promised to change.(maybe we talked to her multiple times, or we'll talk to her again or we won't talk to her again. It could have been jusr once she promised to change and never again.) 📕Examples for "past simple" Ex: I talked to her, and she promised to change. (Maybe I spoke to her jusr once at a specific time. It really doesn't matter to the story and it doesn't matter to the person I'm telling.) 📕Examples for "present perfect progressive" Ex: I have been talking to her, and she promised to change.(Maybe we've talked to her many times, or maybe we just talked to her once earlier today, but it's irrelevant. )

2️⃣Rule: The tense is important to the story, which past tense you choose does matter 📕How many times did talk to her about that? Past simple: We just talked once.(specific instances complete in the past.) Present perfect: We've talked multiple times, and might need to talk again tomorrow.(This is an action happened in the past, but might happen again, or might be repeated action.) Present perfect progressive: We've been talking foe weeks. 👏👏👏We have to know when the grammar actually matters. If tense doesn't matter to the story, you can choose any of these, but if does matter, it's vital that you know which of these tenses to use and why, what it implies about what happened.