There's no past tense in Chinese!
Instead, the Chinese tend to rely on context to indicate that something happened in the past. You can simply indicate that the event happened in the past with a time word like “yesterday” or “two hours ago”. Sometimes you don't need to indicate the past at all.
- 昨天 (zuótiān): yesterday
- 前天 (qiántiān): the day before yesterday
- 上个星期 (shàng ge xīngqī): last week
- 上个月 (shàng ge yuè): last month
- 去年 (qùnián): last year
- 前年 (qiánnián): the year before last
- 以前 (yǐqián): before
- ……前 (qián) ： … ago
- ……的时候 (de shíhou): when …
- past events with 是……的 (shì…de)
- 了 (le) indicates the completion of an action
- 过 (guo4) indicates experiences ever having