Mathematician Grigori Perelman, sometimes in conjunction with mathematicians Richard S. Hamilton and Shing-Tung Yau, ______ credited with proving the ...

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

Sentence 1:

• Mathematician Grigori Perelman,
  • sometimes in conjunction with mathematicians Richard S. Hamilton and Shing-Tung Yau,
  [?] credited with proving the Poincaré conjecture.

Sentence 2:

• Having built on Hamilton's previous work to solve the proof, Perelman
  • has insisted that Hamilton receive credit.

Sentence 3:

• Yau
  • later found and closed gaps in Perelman's proof,
  • persuading some mathematicians that he deserves credit as well.

Understanding the Meaning

Let's start reading from the beginning:

'Mathematician Grigori Perelman' –

• This is who the sentence is about.
• We're talking about one person.

Then we get some additional context:

• 'sometimes in conjunction with mathematicians Richard S. Hamilton and Shing-Tung Yau'
  • This phrase tells us that Perelman is sometimes mentioned together with these other two mathematicians.
  • Notice it starts with 'in conjunction with' – this is giving us extra information about how Perelman relates to others.

Now here's where we need to fill in the blank:

• 'Mathematician Grigori Perelman... ______ credited with proving the Poincaré conjecture.'

Let's look at our choices:

• A. are (plural)
• B. have been (plural)
• C. are being (plural)
• D. is (singular)

What do we notice about the structure here?

• The main subject of the sentence is 'Mathematician Grigori Perelman' – one person, singular.
• The phrase 'sometimes in conjunction with mathematicians Richard S. Hamilton and Shing-Tung Yau' sits between the subject and where the verb goes.
  • This phrase adds context but doesn't change who the subject is.
  • Even though Hamilton and Yau are mentioned, they're inside a descriptive phrase, not part of the main subject.

So we need a singular verb to match 'Perelman': is

Now let's read the rest to see the complete picture:

The second sentence tells us:

• 'Having built on Hamilton's previous work to solve the proof, Perelman has insisted that Hamilton receive credit.'
  • So Perelman used Hamilton's earlier work and wants Hamilton to get credit too.

The third sentence adds:

• 'Yau later found and closed gaps in Perelman's proof, persuading some mathematicians that he deserves credit as well.'
  • Yau fixed some problems in Perelman's proof, so some people think Yau should get credit too.

The complete picture is about how credit for proving this mathematical conjecture is shared (or should be shared) among these three mathematicians, but the main sentence structure focuses on Perelman as the primary subject.

The correct answer is D. is

Grammar Concept Applied

Subject-Verb Agreement with Phrases Between Subject and Verb

When a descriptive phrase comes between the subject and the verb, the verb must still agree with the main subject, not with any nouns that appear in the intervening phrase.

The pattern:

• Subject (singular or plural)
• + Descriptive phrase (may contain nouns of different number)
• + Verb (must match the SUBJECT, not the phrase)

Common phrases that don't change the subject:

• 'in conjunction with...'
• 'along with...'
• 'as well as...'
• 'in addition to...'
• 'together with...'

Examples:

Example 1:

• The scientist, along with her three assistants, is conducting the experiment.
• Subject: 'The scientist' (singular)
• Phrase: 'along with her three assistants' (contains plural noun)
• Verb needed: 'is' (singular, matching 'scientist')

Example 2:

• The students, in addition to their teacher, are attending the conference.
• Subject: 'The students' (plural)
• Phrase: 'in addition to their teacher' (contains singular noun)
• Verb needed: 'are' (plural, matching 'students')

In this question:

• Subject: 'Mathematician Grigori Perelman' (singular)
• Phrase: 'sometimes in conjunction with mathematicians Richard S. Hamilton and Shing-Tung Yau' (contains plural noun)
• Verb needed: 'is' (singular, matching 'Perelman')

The key is to identify the true subject of the sentence and not be distracted by other nouns that appear in phrases between the subject and verb.