Q: I’m writing a letter and am uncertain whether subjects joined by and should be singular or plural. So which sentence is correct: Your passion and commitment to my company HAVE inspired many, or, Your passion and commitment to my company HAS inspired many? —Carrie G.
This kind of thing used to trip me up, too, as a subject with multiple nouns in it seems like it should always be plural. But that isn’t always the case. The way you group the items determines whether it’s a singular subject or a plural subject (and whether you’d use the plural verb have or the singular has). Let me explain.
Sentence subjects that have independent nouns connected by and are plural, thus requiring plural verbs (such as have). One trick to tell if the nouns are independent from each other is to divide the sentence into two sentences and see if the meaning stays the same. For example: The baseball players and the manager were disappointed after losing the big game. When divided, the sentences read: The baseball players were disappointed after losing the big game. The manager was disappointed after losing the game. The meaning is the same and these nouns are thus independent of each other, making the original sentence a plural sentence and requiring a plural verb (were).
Let’s apply this trick to the sentence in question, Your passion and commitment to my company have inspired many. It can be divided into two sentences and keep the same meaning (Your passion to my company has inspired many; your commitment to my company has inspired many), therefore it’s plural and requires the plural verb have.
Not all subjects using and to connect nouns are plural, though. Sentence subjects that have multiple nouns connected by and that refer to a singular thing require singular verbs. Consider, Green eggs and ham was Sam-I-Am’s favorite dish. In this sentence, green eggs and ham is one specific dish in and of itself, so you use the singular verb was. If you divide this sentence (Green eggs was his favorite dish/Ham was his favorite dish) you change the meaning—and Sam-I-Am would be pretty disappointed if you had him over for dinner and served only half of his favorite meal.
When in doubt, divide the sentence to see which verb you need. It will help you on your grammatical quest toward subject/verb agreement.
No matter what type of writing you do, mastering the fundamentals of grammar and mechanics is an important first step to having a successful writing career.