One clause, three slips
the detail turns into an error
A relative clause adds detail to a noun. Pick the wrong pronoun, or repeat the subject, and the detail backfires.
The tunnel, thatnot 'that' after a comma opened in May, saves time for drivers whichpeople: who or that use it, but the people who theydoubled subject live nearby dislike it.
Band 7 (Writing): “a variety of complex structures.”