$#Trả lời:$

He didnt go home because of being ill

=> Unless he were ill, he wouldn't go home.
$#Giải thích:$
$#Cấu trúc:$

Unless + $S_{1}$ + $V_{2/ed}$ / $be_{was/were}$  + O , $S_{2}$   + would + $V_{1}$ + O .
$\color{red}{\text{Tienmanhhoang}}$

`color{red}{#lgdr}`

Đáp án : Unless he were ill , he would go home .

`-` Biến thể điều kiện loại `2` : Unless + S + V(quá khứ) + O , S + would/could + V-inf + O .