A verb agreement question tests whether a verb matches its subject when a list of nouns comes between them. First, sort the verb forms by number: is, was, and has go with it, while are, were, and have go with they. Then ask who or what the verb is about and find the true subject. Cross out phrases that describe that subject. Nouns inside those phrases don't decide the verb's number, even when they're joined by and.
Hints
- Hint 1
The blank gives a helping verb for developing. Ask who is developing the platform.
- Hint 2
Look at the phrase beginning with of. What does that phrase tell you about the noun before it?
- Hint 3
Set aside the opening phrase and the phrase beginning with of, then replace the subject with it or they.
Step-by-step
Find the true subject
Step 1Sort the helpers by number
Look at the helper before developing an open-source platform, which is the part the choices change. This is subject-verb agreement: the verb must match whether its subject is one thing or more than one. Which forms fit they? The forms have been, are, and were all do, so those forms need a plural subject. We'll use the subject's number to decide, rather than guessing from tense.
- Step 2
Set aside the opening phrase
The sentence opens with In an effort to preserve endangered languages, which tells us why the platform is being developed. Does that phrase name who is developing it? No, so set it aside and look after the comma, where the subject of the blank begins.
- Step 3
Separate the group from its members
What does of linguists, community elders, and digital archivists do in that subject? It tells us who's in a coalition, so we can cross it out without losing the noun that the verb must match. Even though and joins the members listed there, it sits inside the of phrase and doesn't join separate subjects of the blank. That leaves one coalition as the true subject, even though the group includes several kinds of people.
- Step 4
Match the helper to the subject
Shrink a coalition to it, and check the helper with that short subject. Which form completes it ... developing? It has been developing uses the singular helper has, so has been matches the subject and completes the verb phrase. Choice B.