What is the rule about subjects joined by and

Subjects joined by the word ''and'' are usually considered to be plural subjects that require the plural verb form. Subjects joined by the word ''and'' are denominated compound subjects. Nevertheless, compound subjects can be divided by words like ''or'' and ''nor as well.'' Each of these words has different rules about subject/verb agreement.

i agree so i wont repert this question

wheres the passage with the idiom underlined