Subject-verb agreement | Worked example

0:03- [Instructor] Hey there test takers. Let's take a look at this reading and writing test question. Because a cycle of lunar phases, blank, 29.5 days to complete, it's possible to observe two full moons in a single month, one at the beginning, and one at the end.

0:16Okay? Which choice completes the text so that it conforms to the conventions of standard English? If you wanna give this one a try before I break it down, pause the video here. Sweet. Now let's do it together. So it's asking us about the conventions of standard English, which means our focus should be on the grammar of the sentence, but which grammar convention is being tested?

0:39The choices will help us figure that out. So glancing at the choices I see they're all forms of the verb to take, right? And let me check, have taken, take, takes, are taken. They're all in the present tense which tells us all we need to know. This is a subject-verb agreement question.

0:55I wanted to check if they were all present tense because if somewhere in the past and somewhere in the present that would make it a verb-tense question. Okay? So, subject verb agreement questions ask us to match a sentences verb to the right subject, and that means what's being tested is a concept called grammatical number, which is to say it's asking you is the subject of the sentence singular or plural.

1:16In English, verbs change depending on the number of the subject. So singular, one dog eats, right? Two dogs eat. The strategy for these questions, therefore, is very simple. First, we find the subject of the sentence, the word that is doing the verb in the sentence, performing the action, and then we ask, is that word singular or plural?

1:38Is there one of it or is there more than one of it? And then you'll match it to the right verb choice. So let's take the strategy back to the question and look for the subject of the sentence. Let me read the passage again. Because a cycle of lunar phases, blank, something to take 29.5 days to complete, it's possible to observe two full moons in a single month, one at the beginning and one at the end, and okay, this is a complex sentence.

2:02It actually has two clauses in it, and is, therefore has two subjects, right? The second clause has it is, it is the subject and is is the verb, so let's just ignore everything after the comma. I'll just cross it out. We only want to look at this dependent clause that begins with because.

2:20What's the noun that completes in 29.5 days? Is it the singular cycle, or the plural lunar phases? What's doing the taking, right? Check this out. The important thing to note is this, of. Look out for prepositions. It's a cycle. A cycle of what? Lunar phases. So that means that the subject of this clause is cycle, and cycle is a singular word.

2:46One cycle. In fact a cycle, so we're looking for a singular verb. We can do this super quick. Say the subject, and then the verb, and you'll know if it's singular or plural. Choice. (A) A cycle have taken. Nope. Plural. A cycle take. Nope, plural. A cycle takes singular.

3:03Bing. There we go. That's the answer. Let's look at D. A cycle are taking. Nope, that's plural. So C is our answer, right? Once we find the subject and figure out if it's singular or plural, we can quickly test the choices because only one is going to match. Let's revisit that prepositions thing over in our top tips.

3:21Prepositions. Watch out for 'em. Preposition phrases can make it appear that the subject of a sentence is a different word than it actually is, as in the sentence, "A colony of termites has moved into my dining table." Not colony is singular. Termites is plural.

3:38The temptation might be to change has moved to have moved because there are many termites, but the subject of that sentence is colony. So keep an eye out for those preposition curve balls and you'll be good to go. Good luck out there. You've got this.