Question 179·Medium·Form, Structure, and Sense
The research team compared the immune response of children to that of adults, concluding that _____ responses were both faster and stronger.
Which choice completes the text so that it conforms to the conventions of Standard English?
For possessive-noun questions, first decide if the noun should be singular or plural based on the sentence meaning, then decide if you need a possessive form (showing ownership). Once you know you need a plural possessive, check whether the plural is regular (ends in -s) or irregular (does not end in -s). Regular plurals usually take just an apostrophe (students'), while irregular plurals like "children" or "men" take 's (children's, men's). Matching the number (singular/plural) and the possessive form will quickly eliminate wrong options.
Hints
Focus on what the blank is modifying
Look at the word right after the blank: "responses." Ask yourself: does the blank describe who the responses belong to, or something else?
Check the noun’s number
The sentence compares the immune response of children to that of adults. Should the word in the blank be singular or plural to match this comparison?
Think about possessive rules for irregular plurals
The plural of "child" is "children." How do you usually make an irregular plural noun that does not end in -s possessive?
Step-by-step Explanation
Understand what the blank is describing
Read the full sentence: "The research team compared the immune response of children to that of adults, concluding that _____ responses were both faster and stronger."
Ask: Whose responses? The blank must describe the responses that belong to children, so we need a possessive form of "children."
Identify the number and base form of the noun
The base noun here is child.
- Singular: child
- Plural: children (this is an irregular plural, because it does not end in -s)
Because the sentence compares children to adults, we need a plural form (not just one child).
Recall the rule for possessives of irregular plurals
For regular plurals that already end in -s (like "students"), we usually add just an apostrophe to make them possessive ("students'").
For irregular plural nouns that do not end in s (like "children," "men," "women"), we make them possessive by adding 's to the plural form.
So we need the plural "children" made possessive with 's.
Match the correct choice to the rule
We are looking for the plural possessive form of "children" made by adding 's to the irregular plural.
That form is "children's", so the correct answer is D) children's.