C. By being inherently bounded because of the meaning of the verb. Verbs with a built-in terminal point habitually take aspect particle le 了, such as sǐ 死 die, wàng 忘 forget, diū 丢 lose,dǎo 倒 fall, huài 坏 break (as in stop working), mài 卖 sell, and so on.

  1. Wǒ wàng-le guān mén.
    我忘了关门。
    I forgot to shut the door.


  2. Yú sǐ-le.
    鱼死了。
    The fish died.