The Holy Grail of Sentence Errors in the SAT Writing section are subject-verb agreements…

Or rather, the Holy Grail of Sentence Errors is subject-verb agreement.

For those of you who didn’t catch the mistake in the opening, this tip is for you!

The SAT loves testing you on subject-verb agreement—on everything about subject-verb agreement, from number to pronouns to gender. As the name of the grammar concept implies, the subject and its matching verb must agree in all ways at all times!

Seems pretty simple, huh? The writers at the SAT have two favorite ways of tripping you up when it comes to subject-verb agreement: interruption and inversion. Your first and most important task is find the subject and its matching verb, which can be trickier than you think. Be assured, the subject will never be a part of a phrase set off by commas. Take a look at this incorrect sentence which uses “interruption”:

The koala bear, which holds a striking resemblance to bears, are not actually bears.

Notice three things about this sentence. First, between the subject and the verb you’ll find an intervening clause, set off with commas. Second, although the subject is singular (“koala”), the nouns in the intervening clause (“bears”) are plural. Third, the verb is plural: it therefore agrees with the nouns in the interrupting clause but not with the true subject (the singular koala bear). This is ETS’ main trick: separate the noun and its verb with a long, descriptive, distracting phrase (often set off by commas), fill that phrase with nouns that are the opposite of the subject (whether singular or plural), and then add a verb that agrees with the phrase nouns, NOT with the subject. By the time you get to the verb in the sentence, it’ll have been so long since you laid eyes on the actual subject, that the subject-verb disagreement will just pass you by. BE WARY OF THESE LONG DESCRIPTIVE PHRASES! BE WARY OF ANY CLAUSE SET OFF BY COMMAS! THEY ARE SIMPLY DISTRACTIONS!

Another, somewhat less common, way that subject-verb disagreement is disguised on the SAT is through the inversion of sentence order. Normally, the subject comes before the verb, but it is possible to put the verb before the subject. Consider:

In the Greek system of letters there are a vowel called epsilon.

The subject of this sentence is the singular noun ‘vowel.’ You can make this fact apparent by crossing out the prepositional phrases:

In the Greek system of letters there are a vowel called epsilon.

This is clearly erroneous; it should read “there is a vowel…”.

Inverted sentences tend to use the verb ‘to be’ in one of its manifestations (‘am,’ ‘are,’ ‘is,’ ‘was,’ ‘were,’ ‘will be’). They also tend to start with prepositional phrases. If you keep these two facts in mind, you should be able to detect subject-verb disagreement in inverted sentences.

QUICK TIP: Work hard to locate subjects and their matching verbs. Be aware they can often be separated by long phrases and often inversed in the sentence. If you correctly cross out “unnecessary” information, such as prepositional phrases and descriptive clauses, the sentence will still retain most of its meaning, and it will be clear whether the subject and verb agree.