Subject-verb agreement and subject-verb concord refer to the same concept in grammar. Both terms describe the relationship between the subject and the verb in a sentence. In order for a sentence to be grammatically correct, the subject and the verb must be in agreement or concord.
The subject of a sentence is the noun or pronoun that the sentence is about. It is the main focus of the sentence and usually comes before the verb. The verb, on the other hand, is the action or state of being that the subject is performing or undergoing. It is the second most important element in a sentence after the subject.
Subject-verb agreement means that the subject and the verb must agree in terms of number. This means that if the subject is singular, the verb must also be singular. If the subject is plural, the verb must also be plural. For example, “The boy runs” is correct because “boy” is a singular subject and “runs” is a singular verb. “The boys run” is also correct because “boys” is a plural subject and “run” is a plural verb.
Subject-verb concord, on the other hand, refers to the agreement between the subject and the verb in terms of person and tense. This means that the verb must agree with the subject in terms of whether it is first person (I, we), second person (you) or third person (he, she, it, they). It must also agree in terms of the tense that is being used, whether it is present, past or future. For example, “She sings” is correct because “sings” agrees with the third person singular subject “she”. “They will sing” is also correct because “will sing” agrees with the third person plural subject “they”.
In summary, subject-verb agreement and subject-verb concord both refer to the relationship between the subject and the verb in a sentence. They are two different terms for the same concept in grammar. It is important to ensure that your writing has correct subject-verb agreement and concord in order to make it grammatically correct and easily understandable to your readers.