`31.` That old house has just been sold (by them) 

`-` Bị động HTHT: S `+` have/has `+` (adv) `+` been `+` VPII `+` (by `+` O)

`32.` Although the weather was bad, they had a wonderful holiday

`35.` Although the work is hard, he can't support his large family

`-` Although/Even though/Though `+` S `+` V

`=` In spite of/Despite `+` N/Ving

`->` mệnh đề nhượng bộ

33. A new mall will be built (by them)

`-` Bị động với TLĐ: S `+` will `+` be `+` VPII +` (by `+` O)

34. If he doesn't take these pills, he won't be better

`-` Unless `=` If ... not ...

`->` Có Unless thì không còn thể phủ định

`FrozenQueen`

`31)` That old home has just been sold.

`->` that old home là số ít `=>` has

`->` O + be + V3/ed + (by S) + ...

`32)` Although the weather was bad, they had a wonderful holiday.

`->` Although + S + V, S + V + ...

`->` the weather không đếm được `=>` was

`33)` A new mall will be built here.

`->` O + will + be + V3 + (by S) + ...

`34)` If he takes these pills, he will be better.

`->` If + S + V-s/es, S + will + V-inf ...

`->` he là số ít `=>` takes

`35)` Although he works hard, he can't support his large family.

`->` Although + S + V, S + V + ...

`->` can (not) V-inf: có/không thể làm gì

@nene