Mandarin Chinese Grammar for Pimsleur Students/Past tense

Particles/characters used
There are some specific particles, characters or combination of characters used to make sentence past tense:  了 - le 过 - gùo 是 ... 的 - shì ... de 

了 le
了 is used either after the verb or after the sentence to make it past tense. According to Pimsleur tapes, 了 added directly after the verb is for telling a list of things you did in the past. For a simple statement that you did something, just add 了 after the sentence.  我吃午饭了 昨天我吃了早饭，吃了午饭，然后我吃晚饭了 

过 gùo
过 is used to tell that you've had an experience and is added after the verb.  我去过北京</li> <li>我来过这儿</li> </ul>

是 ... 的 shì ... de
This is used to tell or ask something detailed about the past. 是 is added after the subject and 的 at the end of the sentence. <ul> <li>你是什么时候去北京的？</li> <li>我是跟我的朋友一起看电影的</li> </ul>