<p>So this question was on practice test 10 of the Blue Book:</p>
<p>(A. Introducing) new ideas and replacing (B. old ones) (C. is) always a high controversial matter, (D. especially when) there is already tension between an older and a younger generation. (E. No error)</p>
<p>The correct answer was E. I picked C, however, because I thought that "introducing new ideas and replacing old ones" counted as multiple things. I understand that this contradicts with the singular "matter", but could someone please explain why, even though two parts each hint at a different form, that the singular form is the correct one?</p>
<p>Your focusing on the “and” part of the clause, and because “and” always means two or more things, you thought the verb must be plural. </p>
<p>Right now, I assume you are thinking “new ideas” and “old ideas” are the subject but that’s not the case. The subject is the INTRODUCTION of the new ideas and the replacement of old ones… taking something in while taking something out. The INTRODUCTION is singular thus the verb must be singular.</p>
<p>If you don’t get it, try saying it aloud. “Introducing new ideas and replacing old ones are always a highly controversial matter…” It sounds weird and awkward because it is wrong.</p>
<p>Introducing new ideas and replacing old ones are always highly controversial matters, especially when there is already tension between an older and a younger generation.</p>
<p>is also a correct sentence.</p>
<p>My sense is that it is. This sentence has a subtle but different meaning than the original. </p>
<p>But there are clear and unambiguous cues in the original sentence that insist on a “singular”, specifically “a” and “matter”. Neither of these words is subject to change. So the intent of the writer is as JoshOS describes.</p>