Question 162·Hard·Form, Structure, and Sense
Not only ______ to map every known coral reef, but it also developed an open-source platform that allows scientists to share real-time data on ocean temperatures and acidity levels.
Which choice completes the text so that it conforms to the conventions of Standard English?
For Standard English conventions questions like this, first identify the sentence structure around the blank—here, the correlative pair "not only ... but also." Check that the words you insert form a complete clause (subject + conjugated verb), maintain parallel structure with the other part of the pair, and match the tense used elsewhere in the sentence. When a negative or limiting phrase like "Not only" begins a sentence, remember to look for subject–auxiliary inversion ("did the initiative aim") and quickly eliminate choices that ignore this pattern or create tense mismatches or fragments.
Hints
Focus on the structure after "Not only"
Look at the phrase "Not only ______ to map every known coral reef, but it also developed..." — what kind of word group (clause vs. phrase) do you need after "Not only" so the sentence is complete?
Think about verb tense
The second part of the sentence uses the verb "developed." Should the missing verb idea before the comma be in the past, present, or another form to match it?
Remember inversion after "Not only"
When a sentence starts with "Not only," how does that often change the order of the helping verb (like "did") and the subject (like "the initiative") in the first clause?
Step-by-step Explanation
Recognize the sentence pattern
Look at the structure:
"Not only ______ to map every known coral reef, but it also developed an open-source platform..."
This is a correlative structure using "not only ... but also." After "Not only," you need a complete clause that will be parallel to the clause after "but it also" ("it also developed...").
Check for a complete clause after "Not only"
A complete clause needs a subject and a finite (conjugated) verb.
Read each option in the blank:
- "Not only the initiative aimed to map..." (subject and verb, but check if word order is natural)
- "Not only [option B] to map..." (has subject and verb, but with different word order)
- "Not only the initiative aims to map..." (subject and verb, check tense and order)
- "Not only aiming to map..." (this is just a participle; by itself it cannot be the main verb of a clause)
Right away, "aiming" is not a full clause because it does not give a complete subject–verb statement, so that option can be eliminated.
Match the verb tense and consider word order
The second clause says "but it also developed an open-source platform," which is in the past tense. To keep the sentence consistent, the first clause should also refer to a past action.
So a present-tense verb like "aims" does not match the past-tense "developed," making that option incorrect.
Now focus on the remaining past-tense options and how they fit after "Not only" at the beginning of the sentence. When a sentence starts with a negative or limiting phrase like "Not only," standard English usually inverts the order of the subject and the helping verb (similar to a question), forming a pattern like:
- "Not only did [subject] [base verb]..., but..."
Choose the option that uses correct inversion and tense
We need a version of the clause that:
- Refers to the past, to match "developed"
- Forms a complete clause
- Uses the inverted pattern with a helping verb before the subject after initial "Not only"
The only choice that does all of this is "did the initiative aim", giving the sentence:
"Not only did the initiative aim to map every known coral reef, but it also developed an open-source platform that allows scientists to share real-time data on ocean temperatures and acidity levels."
This sentence is grammatically correct, uses proper inversion, and maintains clear, parallel structure.