Few things wreak havoc with a happy marriage, a profitable partnership or a grammatical sentence like a lack of agreement. Take this sentence, for instance, which lurched out at me from the pages of a travel magazine:

• The international lineup of wines offer a taste for every palate.

You have to wonder what the author and editor were tasting while preparing the article, because the sentence features a classic lack of agreement: the verb (offer) does not agree with its subject (lineup).

This error is classic because it mirrors the pattern of most agreement errors. The author (or editor), perhaps helped by a nice Shiraz, was distracted by the prepositional phrase of wines, whose plural sense makes it easy to forget that the simple (or main) subject of the sentence is the singular lineup. Prepositional phrases often lead writers astray because of their proximity to the verb: "wines offer" sounds better than "wines offers." That’s why ignoring your ear is a wise idea when checking agreement.

Regardless of how things sound, agreement is based on a straightforward principle: the verb agrees with its simple subject—the main noun or pronoun in the subject minus any modifiers. Modifiers include adjectives or groups of words (such as prepositional phrases) that describe the simple subject.

It’s a straightforward principle, but it can sometimes go horribly wrong.

Prepositions in disguise

When does a prepositional phrase not look like a prepositional phrase? When the preposition involved replaces and. Here are some examples:

• along with
• as well as
• besides
• coupled with
• in addition to
• together with

All of these prepositions mean roughly the same thing as and, but grammatically speaking they are poles apart. As prepositions, their job is to begin prepositional phrases, which can only modify the simple subject, not add to it. Consider this sentence:

• An autographed photo of Matt Damon, along with several dictionaries and manuscripts, takes up most of the space on the translator’s desk.

To many, the verb in this sentence sounds wrong. As with the magazine example above, the ear favours "manuscripts take." But as is so often the case with grammar, our brain must control our ear. The simple subject is photo, which is singular. The along with phrase, because it’s a prepositional phrase, modifies the singular subject rather than adding to it.

Note that the commas in the above example play no part in the agreement. True, they make the prepositional phrase parenthetical, or less essential to the sentence, but they don’t affect the number of the simple subject. Similar sentences without commas follow the same rule:

• Esmerelda together with her minions supports the Dark Queen in all her endeavours.

Here, the simple subject is the singular Esmerelda; once again, the together with phrase merely modifies. The sentence sounds awkward, but it’s correct.

Of course, awkward wording is never a good thing, even when it’s correct. One way to be both natural and correct in a sentence like the one above is to use and in the subject instead of a preposition. And, as a coordinating conjunction, coordinates words, putting them on an equal grammatical footing. In the example above, and would make both Esmerelda and minions into simple subjects, and the verb would become plural, support.

And—not always what it seems

Normally and is a reliable conjunction. It creates a compound out of two or more subjects, a compound that’s nearly always plural. But occasionally and gets gluey and joins subjects so closely that they become one. This happens when the subjects refer to a single activity, concept or person.

• Drinking and driving remains a major cause of highway fatalities. (drinking and driving is a single activity)
• Tortilla chips and sour cream dip is the only fattening snack Bill cannot deprive himself of when training for the Iron Man competition. (tortilla chips and sour cream dip is one snack, not two)
• The editor-in-chief and senior writer of the fraternity magazine is Eldon Wimple Jr. (editor-in-chief and senior writer refers to one person)

A word of warning: for this unusual treatment of and to kick in, the parts of the compound subject must truly refer to a single thing. How would you handle this sentence?

• Maria’s merry disposition and her recognized success in business makes/make her popular in the community.

It’s tempting, especially if relying on what sounds good, to choose makes, the singular. But look carefully. Maria’s disposition, her personality, is one thing; her success in the business world is another. The subjects are closely related, but they are separate concepts and are therefore plural. The right choice is make.

Or and nor—shifty sidekicks of and

What and hath joined together, or and nor put asunder. As coordinating conjunctions, or and nor create compound subjects just as and does, but their meaning keeps the subjects apart. Think about it—if you are going on this trip or that trip, you are not going on two trips.

The separation imposed by or and nor makes these two conjunctions difficult to agree with. Happily, the rule for or and nor, though little known and seldom followed, is simple. The verb always agrees with the subject that is closer to it in the sentence. Ironically, given the pitfalls of proximity we looked at earlier, this is one time when closeness counts.

• Esmerelda or her minions regularly visit the Dark Queen. (verb agrees with minions)
• Neither tortilla chips nor sour cream dip is a particularly nutritious or low-fat snack. (verb agrees with dip)
• Either Maria’s successful business strategies or her merry disposition has won her the admiration of many. (verb agrees with disposition)

All three of these sentences are correct, but the last two, because they involve plural subjects but singular verbs, may sound odd to some. In the interest of both being right and sounding right, it might make sense to reverse the subjects.

• Neither sour cream dip nor tortilla chips are particularly nutritious or low-fat snacks. (verb agrees with chips)
• Either Maria’s merry disposition or her successful business strategies have won her the admiration of many. (verb agrees with strategies)

These are just some of the constructions that can interfere with subject-verb agreement in an otherwise harmonious sentence. For others, see More Dubious Agreement.

Test yourself