Question

Underline the subodrinate clouses

Before he could go swimming, Ali packed his towel.
The twins asked Dad to turn up the heating as it was cold.
After drinking his water, Mark washed up his glass.

Answer 1

The subordinate clauses are before he could go swimming
as it was cold
after drinking his water

Answer 2

Before he could go swimming

as it was cold

after drinking his water