Identify the subject to which the verb will be attached. If you are uncertain of the subject of your sentence, identify the thing that the verb will describe. In the sentence, "He goes far," the subject is "he" who goes.
Note whether the subject is one thing or two. Where the subject is two or more items, the subject is plural. However, in some cases two items in a subject comprise one thing, such as "iced tea and lemon," and are, thereby, treated as a singular subject.
Attach a single verb to a single subject. The single verb should end in -s or -es depending on the word. Add -s to verbs that end in a consonant. Add -es to verbs that end in a vowel.
Use a single verb if the subject described is an either/or or neither/nor statement. For example, "Either Jane or Mrs. Fairfax receives the mail."
Apply use of single verbs when the subject is separated by a clause containing "along with, as well as besides or not." Single verbs must also be used with periods of time and sums of money.