Thanks fireflytech for pointing that out. It's true that I'm looking from a native speaker's persepective, thus it might not be very clear or goes with a learning concept. Anyway i just want to add on a little bit further =) Run vs Ran In english, we have different forms of a word to show past tense, past present tense etc. However in chinese, 跑 is just 跑, what we can do to show it as 'I ran', is to say it in another way with the same meaning - 'I finished running.' I run - 我跑 I run along the path - 我沿着路跑 I ran - direct translate should be 跑了, but limited ways we can use it. I ran for 40kilometers. 我跑了40公里 The more common one that we're looking for is: I ran - (change to) I finished running - 我跑完了 I've （already) ran - i've finished running already 我已经跑完了 (eg answering to your coach when asked whether u've ran?) fireflytech pointed out an interesting fact: the usage with 过 你吃过饺子吗？- have you ever eaten dumplings? However, whole sentence do change if u add another '了‘ 你吃过饺子了吗？ Have you eaten dumplings already? (eg mum cooked a plate of dumplings for you, after a while she checks on you, asking you whether u've eaten them already?' If you're asking someone whether they eaten their meals. 你用过餐了吗？ more polite way 你吃过了吗？common way When answering: 用过了 I had my meal 吃过了 I've eaten Or a more common/friender way people ask: 吃饱了吗? "Have you eaten (very full) already?" 吃饱了 "Eaten. (very full :P)" 过: like fireflytech said, it's like 'ever' 了: a combination word to show something you did has become 'past' 吃 - 吃了, 去 - 去了 etc. ...过了...: somehow like... 'been/finished'?, mostly use for question and answer. Eaten already? 吃过了吗？Eaten. 吃过了。 Present tense is '正在' 我正在吃(东西) I am now eating (something) Good luck to your learning, I'm sure you'll get use to them when you see more/listen more, you'll get the natural flow once you're familiar with it. =)

I think the xaiver answer is a little confusing as he is looking at it from a native speaker perspective. Let me show you from a learning chinese perspective. Chinese is a very Contextual language. you can say past just by implying that the event took place yesterday, last week, last year, last night etc. However, the grammar goes like this. Chinese basic past tense uses two characters that are stuck after the verb or the end of the sentence. one is 了le the other is 过 guo. le is used more for a done in the past (could be many times). guo is used as if you have ever done that before in you entire life. ie: 你吃过饺子吗？- have you ever eaten dumplings? 你吃饭了吗？did you eat? one more note I want to make. xaiver above used the sentence 喝完了 he wan le。。meaning finished drinking. I need to explain something there. 完 wan is what you call a complement of result. it is often used after a verb to indicated the action result. wan mean finished. u can also say for example 我写完了。。I finished writing.

Any examples? 曾经 = used to 过去 = past 之前/先前 = recent past 以前 = last time (long ago) 我曾经去过新加坡 = I used to been to Singapore 这些事已成为过去 = These has already been the past. 我之前去过的那家店 = The shop i just went not long ago(recent past, maybe days/weeks etc). 我以前去过那家店 = I've been to the shop last time. I think we can only use past descriptive words to construct a sentence that talks about the past. while there isn't any specific 'past tense' for something we did. 喝水 = drink water 喝过了水 = drank water/ after drinking water 喝完了 = finished drinking example eat: eat ate eaten 吃，吃了，吃过了? something like that.. :)