想不起
xiǎng​bu​qǐ

to be unable to remember

  1. 想 xiǎng verb
    to think
    to think; to consider; to ponder; to reflect on a problem or idea
  2. 不 bu particle
    [potential]
    Used between a verb and its result to show that the action cannot achieve that result; used as the negative form of the 得 de potential construction
  3. 起 qǐ particle
    [capability]
    used after a verb and 得 de or 不 bù to show whether one can afford, endure, or reach a certain standard