湯姆數學不好。

Tom isn't good at math.

Tom is not good at math.

Tom is bad at math.

Source: Tatoeba

Sentence Composition

1 湯姆 Tāngmǔ Tom (name)
2 數學 shùxué mathematics
=3 不好 bùhǎo no good
=3 不好 bùhào to dislike; to be uninterested in