What sometimes surprises museum visitors, is, the actual size of a painting? Which corrected fragment fixes this sentence?

What sometimes surprises museum visitors, is, the actual size of a painting? Which corrected fragment fixes this sentence?

• A. visitors is
• B. visitors are
• C. visitors, is
• D. visitors; is

Answer: (A)

The key idea here is how a sentence starts with a what-clause and uses a linking verb. “What sometimes surprises museum visitors” is a single subject unit, even though it contains the plural noun phrase “museum visitors.” The verb that follows should reflect the number of that whole subject unit, not the number of the internal noun. That means the linking verb should be singular: is. Using are would mismatch because the complement that follows is singular, “the actual size.” The stray commas around is break the flow and make the sentence awkward; removing them keeps the sentence clean and correct. So the correct fragment produces: What sometimes surprises museum visitors is the actual size of a painting?

The key idea here is how a sentence starts with a what-clause and uses a linking verb. “What sometimes surprises museum visitors” is a single subject unit, even though it contains the plural noun phrase “museum visitors.” The verb that follows should reflect the number of that whole subject unit, not the number of the internal noun. That means the linking verb should be singular: is. Using are would mismatch because the complement that follows is singular, “the actual size.” The stray commas around is break the flow and make the sentence awkward; removing them keeps the sentence clean and correct.

So the correct fragment produces: What sometimes surprises museum visitors is the actual size of a painting?