How to Use Parallelism Correctly

Imagine each sentence as an equation that has to be balanced. In math, the goal of an equation is to make both sides as balanced as possible. When you’re writing, imagine that your words need to be similarly balanced. For instance, the sentence, "For my birthday, I want presents and to eat cake,” is unbalanced, because “presents” is a noun, but “to eat” is a verb.^[1]

• The correct way to write the sentence would be to say, "For my birthday, I want presents and cake," since "presents" and "cake" are both nouns.
• However, you could also say, "For my birthday, I want to open presents and to eat cake," since "to open" and "to eat" are infinitive verbs.

Use the same parts of speech throughout a sentence to make it parallel. If you're listing a person's best qualities, for instance, don't mix adverbs and adjectives, or nouns and verbs. Whether you're writing about an object or listing items in a series, your sentence will make more sense if you're consistent with the types of speech you use.

• For example, you wouldn't say, "Sarah loves her cat, her soft blanket, and to watch TV," since "cat" and "blanket" are nouns but "to watch" is an infinitive verb. However, you could say, "Sarah loves her cat, her soft blanket, and watching TV," since "watching" is a gerund, or a verb that acts as a noun.
• To make this sentence even more balanced, you would say, "Sarah loves her cat, her soft blanket, and TV," since these are all nouns. It is always helpful to prioritize sentence clarity when creating parallelism in a sentence.

Check verbs to ensure they're in the same tense and form. In order to be parallel, the verbs in your sentence should be in the same tense. Also, avoid mixing gerunds, such as “eating,” “playing,” or “running,” with infinitives like, “to talk,” “to go,” or “to follow.”^[2]

• For instance, the sentence “She loved riding horses, hated math, and wishes she could travel more,” mixes past tense ("loved" and "hated") with present tense ("wishes"). Instead, you would say, “She loved riding horses, hated math, and wished she could travel more,” which are all in the past tense.

Make sure nouns have the same number. When you're using nouns to refer to general ideas, make sure you're using all singular or all plural nouns. This will make you sound more authoritative, and it help the reader understand what you're trying to say.^[3]

• For instance, it sounds strange to say, "Cats and a dog make great pets," since the word "cats" is plural and "a dog" is singular. Instead, you would say, "Cats and dogs make great pets," since both "cats" and "dogs" are plural.
• If you're referring to specific items, such as "My living room has a couch, two chairs, and a throw rug," it's fine if the noun numbers don't match.

Be consistent when listing items in a series. One of the most prevalent uses of parallelism is when you're writing a list. Whether you’re detailing a list of objects or you’re writing a list of descriptive words, your sentence will be stronger if each item follows the same structure. For instance, the sentence, “Kate is fast, efficiently, and courteous,” doesn’t sound correct, because the word “efficiently” is an adverb, while the other words in the list are adjectives.^[4]

• To correct this, the sentence could either be written, “Kate is fast, efficient, and courteous,” which uses all adjectives, or “Kate works quickly, efficiently, and courteously,” which uses all adverbs.
• Another incorrect example would be, “He wanted to drive cars, go on trips, and being famous,” since the first 2 items in the series are infinitives and the third is a gerund. Instead, you would say, “He wanted to drive cars, go on trips, and be famous,” which uses all infinitives.

Use parallelism on either side of a conjunction. Conjunctions are words like "and," 'but," or "or." When you separate two elements with a conjunction, they should follow the same structure. For instance, “rest and relaxation” is correct because both words are nouns, but “rest and relaxing” is not, since one side of the conjunction is a noun and the other is a verb.^[5]

• Similarly, “I loved seeing you and having met your mother,” is not balanced, since "loved" is in the past tense and "having met" is a perfect participle. Instead, say “I loved seeing you and meeting your mother,” so that both sides of the conjunction are in the past tense.
• Sometimes the conjunction can be replaced with a semicolon, such as in John F. Kennedy’s famous quote, “Ask not what your country can do for you; ask what you can do for your country.” In this case, the parallelism is created by the repetition of the sentence structure.

Match up parts of speech when comparing and contrasting items. When you compare objects using words like “greater than,” “less than,” “as much as,” “better,” or “worse,” the objects on either side of the comparison should follow the same grammatical structure. If you use verbs, they should be the same tense.^[6]

• For instance, you could say, “Flying is much faster than driving,” in which case both items or gerunds. You could also say, "To fly is much faster than to drive," so that both elements are infinitives. However, it would be incorrect to say, “Flying is much faster than to drive,” since "flying" is a gerund and "to drive" is an infinitive.
• The same rules apply for correlative conjunctions, including “either/or,” “neither/nor,” “both/and,” and “not only/but also.”
• For example, you would say, “You can choose either having a party or going on a trip,” in which cause both items are gerund phrases, rather than “You can choose either having a party or to go on a trip." In the second example, "having a party" is a gerund phrase, but "to go on a trip" is an infinitive phrase.