Which of the following describes what it means when subjects and verbs agree they are not separated by interrupting words they have the same ending they are both singular or both plural they describe the same things

The statement in the question describes subject-verb agreement, which is the concept that subjects and their corresponding verbs must match in terms of number (singular or plural). In other words, if a subject is singular, the verb must also be singular, and if the subject is plural, the verb must be plural as well. Interrupting words or phrases, or different words describing the same thing, should not affect the subject-verb agreement.

The description that best fits the concept of subject-verb agreement is: "They are both singular or both plural."