Nouns are people, places, or things. They are typically the subject of a sentence. For example, in the sentence The hospital was very clean, the noun is hospital; it's a place. PRONOUNs replace nouns and make sentences sound less repetitive. Take the sentence Sam stayed home from school because Sam was not feeling well. The word Sam appears twice in the same sentence. Instead, you can use a pronoun and say Sam stayed at home because he did not feel well.

Sounds much better, right?

Because pronouns take the place of nouns, they need to agree both in number and gender with the noun they replace. So a plural noun needs a plural pronoun, and a feminine noun needs a feminine pronoun. In the previous sentence, for example, the plural pronoun they replaced the plural noun pronouns. There will usually be several questions on the English and Language Usage section that cover pronoun agreement, so it's good to get comfortable spotting pronouns.

Examples

Wrong: If a student forgets their homework, it's considered incomplete.

Correct: If a student forgets his or her homework, it's considered incomplete.

Student is a singular noun, but their is a plural pronoun. So this first sentence is grammatically incorrect. To correct it, replace their with the singular pronoun his or her.

Wrong: Everybody will receive their paychecks promptly.

Correct: Everybody will receive his or her paycheck promptly.

Everybody is a singular noun, but their is a plural pronoun. So this sentence is grammatically incorrect. To correct it, replace their with the singular pronoun his or her.

Wrong: When a nurse begins work at a hospital, you should wash your hands.

Correct: When a nurse begins work at a hospital, he or she should wash his or her hands.

This sentence begins in third-person perspective and finishes in second-person perspective. So this sentence is grammatically incorrect. To correct it, ensure the sentence finishes in third-person perspective.

Wrong: After the teacher spoke to the student, she realized her mistake.

Correct: After Mr. White spoke to his student, she realized her mistake (she and her referring to student).

Correct: After speaking to the student, the teacher realized her own mistake (her referring to teacher).

This sentence refers to a teacher and a student. But whom does she refer to, the teacher or the student? To improve clarity, use specific names, or state more specifically who spotted the mistake.

VERBS

Remember the old commercial, Verb: It's what you do? That sums up verbs in a nutshell. A verb is the action of a sentence; verbs do things. 

Verbs must be conjugated to match the context of the sentence; this can sometimes be tricky because English has many irregular verbs. For example, runs is an action verb in the present tense that becomes ran in the past tense; the linking verb is (which describes a state of being) becomes was in the past tense.

Table 5.1. Conjugations of the verb to be

PAST

SINGULAR

PLURAL

was were

PRESENT

is are

FUTURE

will be will be

As mentioned, verbs must use the correct tense, and that tense must make sense in the context of the sentence. For example, the sentence I was baking cookies and eat some dough sounds strange, right? That's because the two verbs was baking and eat are in different tenses. Was baking occurred in the past; eat, on the other hand, occurs in the present. Instead, it should be ate some dough 

Like pronouns, verbs must agree in number with the noun they refer back to. In the example above, the verb was refers back to the singular I. If the subject of the sentence was plural, it would need to be modified to read They were baking cookies and ate some dough.

Note that the verb ate does not change form; this is common for verbs in the past tense.

Examples

Wrong: The cat chase the ball while the dogs runs in the yard.

Correct: The cat chases the ball while the dogs run in the yard.

Cat is singular, so it takes a singular verb (which confusingly ends with an s); dogs is plural, so it needs a plural verb.

Wrong: The cars that had been recalled by the manufacturer was returned within a few months.

Correct: The cars that had been recalled by the manufacturer were returned within a few months.

Sometimes, the subject and verb are separated by clauses or phrases. Here, the subject cars is separated from the verb phrase were returned, making it more difficult to conjugate the verb.

Correct: The deer hid in the trees.

Correct: The deer are not all the same size.

The subject of these sentences is a collective noun, which describes a group of people or items. This noun can be singular if it's referring to the group as a whole or plural if it refers to each item in the group as a separate entity.

Correct: The doctor and nurse work in the hospital.

Correct: Neither the nurse nor her boss was scheduled to take a vacation.

Correct: Either the patient or her parents need to sign the release forms.

When the subject contains two or more nouns connected by and, that subject is plural and requires a plural verb. Singular subjects joined by or, either/or, neither/nor, or not only/ but also remain singular; when these words join plural and singular subjects, the verb should match the closest subject.

Wrong: Because it will rain during the party last night, we had to move the tables inside.

Correct: Because it rained during the party last night, we had to move the tables inside.

All the verb tenses in a sentence need to agree both with each other and with the other information in the sentence.

In the first sentence above, the tense doesn't match the other information in the sentence: last night indicates the past (rained), not the future (will rain).