both…and, either…or, neither…nor: Master the Symmetry Rules of Correlative Conjunctions Once and for All
When writing English sentences, have you ever hesitated over this: Both my brother and I ___ tired. Should you fill in is or are? Or which verb should match in Neither the students nor the teacher ___ here.? These are all questions about "correlative conjunctions." They always appear in pairs. Once you grasp the rules behind them, you will never have to guess again.
Don't worry, this article will give you three practical takeaways that you can use immediately.
What Are Correlative Conjunctions
Correlative conjunctions are conjunctions that appear in "pairs," with one at the beginning and one in the middle, sandwiching the content to be connected. The three most common pairs are:
- both … and … (both... and...)
- either … or … (either... or...)
- neither … nor … (neither... nor...)
Let's look at their respective tones:
- I like both coffee and tea. (I like both coffee and tea.)
- You can have either coffee or tea. (You can choose either coffee or tea.)
- I want neither coffee nor tea. (I want neither coffee nor tea.)
Note that neither … nor itself already carries a negative meaning, so there is no need to add not in the sentence.
Golden Rule 1: The Structures Before and After Must Be Symmetrical
This is the most important rule for correlative conjunctions, called parallel structure. Simply put: whatever part of speech is placed after the first conjunction, the same part of speech must be placed after the second.
Think of it like two sides of a scale; they must weigh the same to be balanced.
- Noun to noun: She speaks both English and Japanese. (She speaks both English and Japanese.)
- Verb to verb: He either walks or cycles to work. (He either walks or cycles to work.)
- Adjective to adjective: The film was neither funny nor scary. (The movie was neither funny nor scary.)
Let's look at a common mistake:
She both likes singing and dancing.✗- She likes both singing and dancing. ✓ (She likes both singing and dancing.)
What is the difference? In the first sentence, both is followed by the verb likes, while and is followed by the noun dancing, making the two sides asymmetrical. In the second sentence, moving both in front of the two gerunds balances both sides with -ing forms.
Test method: Cover the words after each of the two conjunctions and read them separately. If the "types" of the two parts are the same (both nouns, both verbs, both adjectives), they are symmetrical.
Golden Rule 2: both…and Always Uses Plural
This rule is the simplest, just remember: when both … and connects two subjects, the verb is always plural. Because both means "both of them," it is naturally plural.
-
Both my brother and I are tired. ✓ (Both my brother and I are tired.)
-
Both my brother and I is tired.✗ -
Both the manager and the staff agree with the plan. (Both the manager and the staff agree with the plan.)
Easy to remember: when you see both, just use a plural verb without overthinking.
Golden Rule 3: For either / neither, Look at the "Proximity Rule"
This is where most people get stuck, but there is actually a super practical formula: the proximity rule.
When either … or or neither … nor connects two subjects, the verb must agree with "the subject closest to it." That is, look at whether the noun after or or nor is singular or plural.
- Either the teacher or the students are wrong. (Either the teacher or the students are wrong.) → The closest one is students (plural), so use are.
- Either the students or the teacher is wrong. (Either the students or the teacher is wrong.) → The closest one is teacher (singular), so use is.
neither … nor works exactly the same way:
- Neither my parents nor my sister knows the truth. (Neither my parents nor my sister knows the truth.) → The closest one is sister (singular), so use knows.
- Neither my sister nor my parents know the truth. (Neither my sister nor my parents know the truth.) → The closest one is parents (plural), so use know.
How to remember: The verb only "listens" to the subject closest to it; it doesn't care about the far one.
Quick tip: If a singular/plural combination feels awkward to read while writing, you can put the singular subject first and the plural subject second. That way, the verb is plural, which usually sounds the most natural.
One Step Further: not only … but also (B2 Level)
Once you have learned the three pairs above, you can add another more advanced correlative conjunction: not only … but also … (not only... but also...). It can add more layers to your sentences and is a great tool for boosting your writing.
- She is not only a teacher but also a writer. (She is not only a teacher but also a writer.)
- The trip was not only cheap but also fun. (The trip was not only cheap but also fun.)
It also follows the same two rules from before:
- Symmetry: If not only is followed by a noun, but also must also be followed by a noun.
- Proximity Rule: When connecting subjects, the verb agrees with the nearest subject. Not only the players but also the coach was surprised. (Not only the players but also the coach was surprised.)
In spoken English, also is often omitted, leaving just not only … but …, which means the same thing.
Three-Minute Quick Review
Keep this cheat sheet in mind, and you've mastered most of it:
- both … and → The verb is always plural.
- either … or / neither … nor → The verb agrees with the nearest subject (proximity rule).
- All correlative conjunctions → Symmetrical parts of speech before and after (noun with noun, verb with verb).
- neither … nor is negative in itself, do not add not.
To summarize the judgment tip in one sentence: first check if the left and right sides are symmetrical, and then look at the subject after or/nor to determine the verb.
How to Practice on Loopy
Understanding the grammar rules is only the first step. Truly remembering them comes from encountering them time and again in real sentences. Loopy integrates correlative conjunctions like both…and, either…or, and neither…nor into the dialogues and listening scenarios of its graded courses. You will naturally encounter them in A1 to B1 content, at a difficulty level that perfectly matches your current ability.
Follow these steps, and the rules will become second nature to you:
- Use the listen-and-shadow mode to read sentences like Both my brother and I are tired. out loud, making "both with plural" a muscle memory of your mouth.
- When you encounter unfamiliar words (like neither or proximity), open the dictionary to look them up, view example sentences, and listen to the pronunciation.
- Leave the sentence patterns you have learned to memory curve review to arrange spaced repetition, showing up right before you are about to forget them, consolidating your memory time and again.
Don't know which level is suitable for you to start practicing from? Take a few minutes to complete a placement test, and Loopy will help you find the best starting point.