Form a compound subject by linking two or more subject nouns with the conjunction "and." Other conjunctions include "or" and "nor." "Firemen and police officers" is an example of a compound subject joined by the conjunction "and."
Select a verb, depending on the idea you want to express. For example, use the verb "to drive."
Combine the compound subject with the verb to form a "plural compound subject," such as "the fireman and the police officer drive to the scene of the accident." Note that "to drive" reflects the plural of the compound subject.
Utilize alternate forms of the compound subject-verb structure by substituting the word "and" with "or" to form a "singular compound subject." Using the same example, rewrite the sentence as "the fireman or the police officer drives to the scene of the accident." Note that the verb reflects the singular nature of the compound subject, which is always the rule when using "or" in this context. Look at the subject word next to "or" to determine which verb to use; for example, if the subject were "fireman or the police officers," the verb changes to "drive" since "officers" is plural; conversely, if the compound subject were "firemen or the police officers," the verb is still "drives" as "firemen" appears before "or."