Question 154·Easy·Form, Structure, and Sense
During its decade-long migration study, the research team tagged hundreds of monarch butterflies so that _____ flight patterns could be tracked across the continent.
Which choice completes the text so that it conforms to the conventions of Standard English?
For possessive-noun questions, first decide whether the noun should be singular or plural by checking words like "each," "every," or "all" around it. Then decide if the sentence needs possession (ownership) or just a plain noun or plural. Apply the standard rules: singular possessive = singular noun + 's; plural possessive (for regular plurals) = plural noun + apostrophe only. Eliminate any choice that disagrees with nearby words (like using a plural noun after "each") or that misuses or omits the apostrophe.
Hints
Check the word right before the blank
Notice the word "each" comes right after the blank. Think about whether "each" is normally followed by a singular or plural noun.
Ownership vs. description
What is the relationship between the butterflies and the "flight patterns"? Are the butterflies owning something, or just being described? That will tell you whether you need a possessive form (with an apostrophe).
Singular vs. plural and apostrophes
Look for two separate decisions: (1) Should the noun after "each" be singular or plural? (2) Where does the apostrophe go to make that noun possessive?
Step-by-step Explanation
Identify what the missing phrase must do
Read the sentence:
"During its decade-long migration study, the research team tagged hundreds of monarch butterflies so that _____ flight patterns could be tracked across the continent."
The blank comes right before "flight patterns." That means the phrase in the blank must show who owns or has the flight patterns. So you need a possessive form (showing ownership) related to the butterflies.
Decide on singular vs. plural after "each"
Look at the word right after the blank: it starts with "each."
On the SAT (and in standard English), "each" is followed by a singular noun, even if we are talking about many things overall. For example:
- "each student" (not "each students")
- "each car" (not "each cars")
So after "each," we need "butterfly" (singular), not "butterflies" (plural). Any choice that puts a plural noun directly after "each" is wrong.
Form the correct possessive
We have decided the noun after "each" must be singular: "butterfly."
Now we need this noun to be possessive because it is showing ownership of "flight patterns."
To make a singular noun possessive in English, we add 's to the singular form:
- "student" → "student's book"
- "car" → "car's engine"
- "butterfly" → (apply the same rule)
So the correct form must be the singular possessive of "butterfly."
Match the correct grammar to the answer choice
We want a phrase that has:
- "each" + singular noun ("butterfly"), and
- that singular noun in possessive form (add 's).
The only choice that has "each" + singular "butterfly" + 's is D) each butterfly’s.
So the correct answer is D) each butterfly’s.