Pronoun Answer 19

19. An eighteenth century architect was also a classical scholar; they were often at the forefront of archaeological research.

Rewrite:

19. An eighteenth century architect was also a classical scholar; he was often at the forefront of archaeological research.

Why?

Here it looks like "they" is referring back to both "architect" and "scholar", but in the sentence these are the same people. Therefore, the singular "he" is used, and consequently, the verb "was" must agree with the singular form.