The main subject of a sentence is never in a prepositional phrase.
This is why we spent so much time on prepositions last month. If you can find prepositions, you can find prepositional phrases. If you find prepositional phrases, you can isolate them (mentally or with parentheses) and discover that the main subject is not in a prepositional phrase. This will help you determine subject verb agreement in your sentences more clearly.
For example:
1. Kara, (along with her sisters), is coming.
a. Kara is the subject and needs the verb is
b. Sisters is not the sentence’s subject.
2. Josiah and Jake, (though not Jonathan), are at basketball.
a. Josiah and Jake are the subjects of the sentence, not Jonathan.
b. Thus, Josiah and Jake need a plural verb—are.
In review, a sentence’s main subject has the following traits:
a. It is the person or thing that the sentence is about.
b. It usually comes at the beginning of the sentence.
c. It is usually a noun or a pronoun.
d. It is the source (person or thing) of the action.
e. It is never found in a prepositional phrase.
Better study up! Tomorrow is a pop quiz! Smile…