Parallel structure with correlative conjunctions

Parallelism makes paired ideas easier to compare. A sentence can contain the right conjunction and still feel wrong if the structure after the first half does not match the structure after the second. When editing, locate both halves of the pair and compare what each one introduces.

Recognize the common pairs

Common correlative conjunctions include both…and, either…or, neither…nor, whether…or, not only…but also, and as…as. They connect words, phrases or clauses. The joined elements should normally be parallel in grammatical form: “both reading and writing,” “either to revise or to submit,” or “not only did she prepare the report, but she also presented it.”

Match form and function

Compare “The role requires both researching data and to prepare reports.” The first element is a gerund phrase; the second is an infinitive phrase. Make them match: “The role requires both researching data and preparing reports,” or “both to research data and to prepare reports.” Likewise, “The plan is not only affordable but also provides flexibility” pairs an adjective with a verb phrase. Revise to “The plan is not only affordable but also flexible,” or “not only affordable but also flexible enough to adapt.”

Keep each half close to its element

A long sentence can hide which words belong to each conjunction. Put each half near the word or phrase it introduces. In “She not only revised the essay but also checked the citations,” not only and but also introduce parallel verb phrases. Avoid inserting unrelated material between a pair if it makes the comparison hard to follow.

Separate parallelism from agreement

Either-or and neither-nor can raise a separate subject-verb agreement question. Parallel structure asks whether the connected elements have matching grammatical form. Agreement asks whether the verb matches its subject under the construction's rule. Solve both: a sentence can be parallel but have the wrong verb, or have correct agreement but uneven paired elements.

Revision steps

1. Underline both halves of the correlative pair.
2. Mark the grammatical structure each half introduces.
3. Check that the paired words, phrases or clauses match in form and function.
4. Read the sentence aloud to see whether the ideas are balanced.
5. Then check subject-verb agreement and punctuation separately.

Common errors

• “Both analyzing the data and to present the results” mixes a gerund with an infinitive.
• “Not only a clear explanation but also the speaker answered questions” pairs a noun phrase with a clause.
• A long interruption can make the reader lose track of the paired structure.
• Correct parallel structure does not automatically guarantee correct verb agreement.
• Use the pair that expresses the intended relationship; the words are not interchangeable in every sentence.

Key takeaway

After a correlative conjunction, compare the grammatical jobs on both sides. Keep them parallel, then check agreement and meaning as separate editing steps.

Match the grammatical forms on both sides

Correlative conjunctions work in pairs: both…and, either…or, neither…nor, not only…but also, and whether…or. The parts they connect should have the same grammatical form. “The course teaches both analysis and how to write” mismatches a noun with an infinitive phrase. Revise to “teaches both analysis and writing” or “teaches both how to analyze and how to write.” Parallel form makes the relationship easier to process.

The matching elements may be words, phrases, or clauses. “The policy applies either to current candidates or to recent graduates” pairs prepositional phrases. “She not only reviewed the rule but also practiced questions” pairs verb phrases. Identify the two elements governed by the pair and compare their grammatical structure. They need not use identical words, but they should perform the same role.

Place each part near the element it connects

Keep correlative markers close to their parallel elements. “The plan not only reduces cost but improves access” can imply that only reduces cost is the first paired element. Clearer wording is “The plan not only reduces cost but also improves access.” Likewise, “Both the explanation was clear and the example helped” puts both far from the parallel subjects; recast as “Both the explanation and the example were clear and helpful.”

A common error is placing a modifier so that it seems to apply to only one half of the pair. Read the sentence aloud, then temporarily remove the first marker and inspect the second half. If one side is a noun and the other is a clause, the construction may need revision even when the meaning is understandable.

Check verb agreement in either-or and neither-nor pairs

When either-or and neither-nor connect two subjects, standard editing convention usually makes the verb agree with the nearer subject: “Neither the assistants nor the supervisor is available”; “Neither the supervisor nor the assistants are available.” This proximity rule is a separate issue from parallel form. If the subjects differ in number and the sentence sounds awkward, rewrite it to avoid the mismatch when the facts allow.

Both…and normally connects two items as a compound subject and takes a plural verb: “Both the instructor and the candidates are ready.” Do not let the singular form of the first noun control the verb when the conjunction creates a compound subject. Check the whole subject and its relationship to the verb.

• Identify the two elements connected by the correlative pair.
• Match parts of speech and grammatical roles.
• Keep not only/but also and other markers close to their elements.
• Check subject-verb agreement separately, especially with either-or and neither-nor.
• Rewrite mismatched constructions when a clearer sentence is possible.

Match the grammatical forms after each pair

Correlative pairs connect elements that have equal grammatical weight. With both…and, the two sides should match: “The lesson both reviews vocabulary and applies it in a discussion.” Each side is a verb phrase. “The lesson both reviews vocabulary and an application discussion” mismatches a verb phrase with a noun phrase. A revision can either make both sides verbs or both sides nouns. Check the meaning after revising so the parallel form does not create a new claim.

The same check applies to either…or and neither…nor. “Students can either summarize the passage or compare its claims” pairs two verbs with matching objects. When a pair links subjects, place it close enough to show the intended grouping. “Either the teacher or the students are responsible” uses a verb that agrees with the nearer plural subject under the conventional proximity rule; a rewrite can avoid a distracting choice: “The teacher is responsible, or the students are.” On an editing question, identify the paired elements first, compare their forms, then assess agreement and punctuation separately.