The basic idea behind sentence agreement is pretty simple: all the parts of your sentence should match (or agree). Verbs need to agree with their subjects in number (singular or plural) and in person (first, second, or third). In order to check agreement, you simply need to find the verb and ask who or what is doing the action of that verb.

Person

Agreement based on grammatical person (first, second, or third person) is found mostly between verb and subject. For example, you can say “I am” or “he is,” but not “I is” or “he am.” This is because the grammar of the language requires that the verb and its subject agree in person. The pronouns I and he are first and third person respectively, as are the verb forms am and is. The verb form must be selected so that it has the same person as the subject.

Number

Agreement based on grammatical number can occur between verb and subject, as in the case of grammatical person discussed above. In fact the two categories are often conflated within verb conjugation patterns: there are specific verb forms for first person singular, second person plural and so on. Some examples:

• I really am (1st pers. singular) vs. We really are (1st pers. plural)
• The boy sings (3rd pers. singular) vs. The boys sing (3rd pers. plural)

More Examples

Compound subjects are plural, and their verbs should agree. Look at the following sentence for an example:

A pencil, a backpack, and a notebook were issued to each student.

Verbs will never agree with nouns that are in prepositional phrases. To make verbs agree with their subjects, follow this example:

The direction of the three plays is the topic of my talk.

The subject of “my talk” is direction, not plays, so the verb should be singular.

In the English language, verbs usually follow subjects. But when this order is reversed, the writer must make the verb agree with the subject, not with a noun that happens to precede it. For example:

Beside the house stand sheds filled with tools.

The subject is sheds; it is plural, so the verb must be stand.

Agreement

All regular verbs (and nearly all irregular ones) in English agree in the third-person singular of the present indicative by adding a suffix of either -s or -es.

Look at the present tense of to love, for example:

The highly irregular verb to be is the only verb with more agreement than this in the present tense:

Consistency

One of the most common mistakes in writing is a lack of tense consistency. Writers often start a sentence in one tense but ended up in another. Look back at that sentence. Do you see the error? The first verb start is in the present tense, but ended is in the past tense. The correct version of the sentence would be “Writers often start a sentence in one tense but end up in another.”

These mistakes often occur when writers change their minds halfway through writing the sentence, or when they come back and make changes but only end up changing half the sentence. It is very important to maintain a consistent tense, not just in a sentence but across paragraphs and pages. Decide if something happened, is happening, or will happen and then stick with that choice.

Read through the following paragraphs. Can you spot the errors in tense? Type your corrected passage in the text frame below:

If you want to pick up a new outdoor activity, hiking is a great option to consider. It’s a sport that is suited for a beginner or an expert—it just depended on the difficulty hikes you choose. However, even the earliest beginners can complete difficult hikes if they pace themselves and were physically fit.

Not only is hiking an easy activity to pick up, it also will have some great payoffs. As you walked through canyons and climbed up mountains, you can see things that you wouldn’t otherwise. The views are breathtaking, and you will get a great opportunity to meditate on the world and your role in it. The summit of a mountain is unlike any other place in the world.