[译] 她必须花许多时间照料她生病的母亲。
[误] She had to spend much time looking after her ill mother.

[正] She had to spend much time looking after her sick mother.
[注] Ⅲ表示"生病的"，通常用作表语，作定语时，意思有改变，表示"邪恶的"，而 sick 通常用作定语。所以误句中的 Ⅲ必须改成 sick。