1. Subject–verb Pronoun–antecedent DATA is a Plural word
Agreement
Subject–verb
Pronoun–antecedent
DATA is a Plural word
In this lecture, you will learn how to ensure agreement between subjects and verbs and between pronouns and their antecedents.
For additional instruction on this topic, refer to the Pronoun Antecedent Agreement section of the Grammar module in D2L.

2. Subject-Verb Agreement
The subject of the sentence must agree with the verb that describes the behavior of the subject:
The boy wants to go to the movies.
The boys want to go to the movies.
The dog is playing.
The dogs are playing.

3. Subject-Verb Agreement with a Twist
Correct
Incorrect
A random sample of 100 female students was selected for the study
The sample and was are in agreement with each other. The prepositional phrase (of 100 female students) is irrelevant to the determination of agreement.
A random sample of 100 female students were selected for the study
The subject (the random sample) and the verb (were) are not representing the same number.
When a prepositional phrase comes between the subject and verb, maintaining agreement can be tricky.
In the correct example, it is important to note that the subject and the verb are in agreement with each other. It is also important to understand that the object of the preposition (students) is not the subject of this sentence, so it has no influence on selection of the correct verb (was).

4. Pronoun–Antecedent Agreement
Antecedent = A word that comes before and “refers to” the pronoun (antecedent, 2014, definition 1) .
The pronoun and antecedent must agree, which means they must be the same in number.
Lisa looks through the APA manual, which she cherishes dearly.
The students look through the APA manual, which they cherish dearly.
Agreement can be explained in terms of numbers
Two options
1. Singular
2. Plural
Lisa is one person; therefore, the pronoun referring to her, she, must be singular.
The students are more than one person; therefore, the pronoun referring to them, they, must be plural.
Antecedent. (2014). In Merriam-Webster online dictionary. Retrieved from

5. Pronoun–Antecedent Agreement
Correct Agreement
Incorrect
I will assign each participant to complete the survey at his or her own desk.
The antecedent (the participant) is singular and is in agreement with the singular pronoun (his or her).
I will assign each participant to complete the survey at their own desk.
The antecedent (the participant) is singular and is NOT in agreement with the pronoun (their), which is plural.
Notice in the correct example, participant is singular and so are the pronouns his and her. It is important to say “his or her own desk” instead of “his own desk” because we do not know the sex of each participant from this sentence alone.

6. Pronoun–Antecedent Agreement
Correct Agreement
Incorrect
The researcher instructed the participants to eat one apple each day for 2 weeks at their homes.
Participants and their are plural; therefore, they are in agreement with each other.
Each student turned in their papers on time.
The antecedent (student) and the pronoun (their) are not representing the same number.
Student = singular
Their = plural
When writing, always check for agreement between pronouns and antecedents.
The correct version of the incorrect example above is:
Each student turned in his or her paper on time.
Note that paper is singular when the subject (student) is singular, but that papers is plural when discussing more than one student:
All of the students turned in their papers on time.

7. Data The word data is a plural noun:
The data are ready for analysis
Very few people are aware of this fact; you will see people treating data as a singular noun all the time.
The singular form of data is datum, but I have never heard this word used except to state the fact that this is the singular form.
Data is a mass noun, so:
Less data, but fewer data points
A large amount of data, but a large number of data points
Milk is a mass noun, but a glass (of milk) is a count noun.
Similarly, data is a mass noun, but data point is a count noun.
For more examples see p. 78 of the APA manual.