A verb agreement question tests whether the verb fits a subject naming one thing or more. Sort the forms using it for one thing and they for more, then find the true subject. Cross out extra phrases to see who or what the verb describes. Subjects joined by and take a plural verb, while along with adds detail without changing the subject’s number. The verb must match that subject, not the noun nearest the blank.
Hints
- Hint 1
In the sentence with the blank, ask what does the encouraging. Look for the words that name it.
- Hint 2
Set aside the explanation between the dashes and examine how along with works. Does it join two subjects, or give more detail about one?
- Hint 3
Once you’ve found the subject, replace it with it or they and test the verb forms. Which forms can go with the word you chose?
Step-by-step
Sort, find the subject, and match
Step 1Sort the verb forms
Start with the forms of encourage: which ones go with they? encourage, have encouraged, and were encouraging all do, but none works with the singular pronoun it. Number comes before tense because these forms can be ruled out if the subject is singular. The verb must agree with whatever leads readers to think beyond human timescales.
- Step 2
Find the main noun
What in the book leads readers to think that way? Start with “the idea of” and set aside the explanation the recognition that Earth’s history is vast and interconnected. That explanation tells us what timefulness means, but it doesn’t add another subject for the blank. The opening In geologist Marcia Bjornerud’s recent book tells us where the idea appears, so the main noun is idea.
- Step 3
Check whether the examples change the subject
Does along with vividly described examples of geological processes make the subject plural? No: along with adds information, while and would join two subjects. The examples are things included with the idea, not a second subject joined to it. Cross out that whole phrase, including the plural nouns examples and processes. Only idea controls the verb’s number, even though those plural nouns sit closer to the blank.
- Step 4
Match one idea with a singular verb
Shrink “the idea” to it: which form works now? In the present tense, a verb for one thing usually ends in -s, so the short version is it encourages. Here, -s marks a singular verb, unlike the plural -s on nouns. That gives us encourages for the blank. Choice C.