Since Dickens is the singular subject, the verb should also be singular.
Dickens, as well as Trollope and Thackeray, was writing . . .
Dickens, as well as Trollope and Thackeray, were writing novels depicting English life and customs when Victoria was queen.
What is the mistake in this sentence.
2 answers
Ms. Sue is right. The words between the commas are not part of the subject.
1 answer