您记性不太好。

Your memory isn't too good.

Source: Tatoeba

Sentence Composition

1 您 nín you (courteous, as opposed to informal 你 nǐ)
=2 记性 jìxing memory (ability to retain information)
=2 记性 jìxìng ability to remember; memory (as opposed to what is remembered)
3 不太好 bùtàihǎo
  1. not so good
  2. not too well