Question 112·Easy·Boundaries
During his keynote speech on environmental stewardship, Dr. Nguyen posed a challenge to the audience: Who _____
Which choice completes the text so that it conforms to the conventions of Standard English?
For Standard English boundary questions that involve punctuation and sentence endings, first identify whether the clause in question is a statement or a question, especially when it follows a colon or quotation. Look for question words like “who,” “what,” “why,” or “how” and decide if the author is directly asking something. Then read each option in the full sentence to check for natural word order (subject + verb) and matching end punctuation (question mark for questions, period for statements). Eliminate any choice that sounds awkward or whose punctuation doesn’t match the sentence type.
Hints
Look at the colon
The colon in the sentence introduces the specific words of the challenge Dr. Nguyen posed. Think about what kind of sentence those words are.
Think about the word “Who”
When a sentence begins with “Who,” is it usually a statement or a question? What type of punctuation normally comes at the end of that kind of sentence?
Check the word order
Say each option in your head after the word “Who.” Which ones sound like natural, correct English word order, and which sound mixed up?
Match punctuation to sentence type
Once you know whether the words after the colon form a question or a statement, choose the option whose final punctuation mark matches that sentence type.
Step-by-step Explanation
Understand what the colon is doing
The sentence says, “Dr. Nguyen posed a challenge to the audience: Who _____”. The colon introduces the exact wording of the challenge. Since it begins with “Who,” this wording is a question Dr. Nguyen asked his audience.
Decide on the correct word order after “Who”
In English questions that start with “Who,” the normal pattern is:
- Who + verb “is” + complement
So we say “Who is responsible…,” not “Who responsible is….” The word “responsible” is an adjective that must come after the linking verb “is,” not before it.
Choose the correct end punctuation
Because the words after the colon are a direct question (they start with “Who” and ask something of the audience), they must end with a question mark. Ending this question with a period would be incorrect.
Select the choice that matches both grammar and punctuation
The correct completion must:
- Use the word order “Who is responsible …” (not “Who responsible is …”), and
- End with a question mark, because it is a direct question.
The only choice that does both is:
“is responsible for protecting the planet we all share?”