Lesson 29

Correlative Conjunctions and Parallel Structure

This lesson groups five rules that students commonly confuse because they look similar on the surface. Check both the logical relationship and the grammatical shape on each side. Work through the examples slowly once; speed comes after the pattern is clear.

5 rules10 questionsGrammar practice

What you will learn

Understand and apply: 'Both ... and' should join parallel structures.
Understand and apply: 'Either ... or' should join parallel alternatives.
Understand and apply: 'Neither ... nor' should join parallel negatives.
Understand and apply: 'Not only ... but also' should preserve parallelism.
Understand and apply: Do not normally pair 'although' with 'but' in the same clause structure.

For every rule: spot the trigger → identify the grammatical relationship → apply the form → check meaning.

Before you start

Try the warm-up without checking the rule. The purpose is to expose the instinct you currently use, not to score marks.

Which sentence follows the target grammar pattern?

A. She is both accurate and efficient.

B. She both is accurate and works efficiently.

Answer: A. The elements after both and and should have the same grammatical form.

Rule 1 · G141

'Both ... and' should join parallel structures

The elements after both and and should have the same grammatical form.

Correct example

She is both accurate and efficient.

Incorrect example

She both is accurate and works efficiently.

Interpretation

The elements after both and and should have the same grammatical form. In a test, do not memorise this as an isolated sentence. Check both the logical relationship and the grammatical shape on each side. The correct example shows the pattern in context; compare it directly with the incorrect version and identify the exact word that must change.

Why it matters

Connectors determine both logic and parallel structure, which makes them useful exam traps.

Common exam trap

The two halves express the right idea but are not grammatically parallel.

How to spot it

Split the sentence at the connector and compare the grammatical form and logic on both sides.

3-step solving method

Name the logical relationship.
Split the two linked elements.
Make their grammatical forms parallel.

Why the incorrect example fails

The target structure requires this rule: The elements after both and and should have the same grammatical form. In the incorrect version, the repair is to add “is”; remove “is”; replace “works efficiently.” with “efficient.”. That is the exact edit a student should be able to justify in an error-spotting question.

Nuance and memory hook

A connector can be grammatically correct but logically wrong; check cause, contrast, condition and addition separately.

Paired connector, paired grammar.

Quick check

Without relying on what 'sounds right', explain which part of this sentence violates the rule: “She both is accurate and works efficiently.”

Reveal quick check answer

Apply 'Both ... and' should join parallel structures: The elements after both and and should have the same grammatical form.

Practice questions

Apply the rule in context

Which sentence is the better choice in standard exam-oriented English?

A. She is both accurate and efficient.B. She both is accurate and works efficiently.

Explain the error rather than guessing by sound

Why is this sentence problematic in the target rule? “She both is accurate and works efficiently.”

A. The target structure requires this rule: The elements after both and and should have the same grammatical form. In the incorrect version, the repair is to add “is”; remove “is”; replace “works efficiently.” with “efficient.”. That is the exact edit a student should be able to justify in an error-spotting question.B. If meaning is clear, parallel grammar does not matter.C. Although must be followed by but.D. Because must be paired with so.

Rule 2 · G142

'Either ... or' should join parallel alternatives

Place either and or so that the alternatives they introduce match grammatically.

Correct example

You can either revise the notes or attempt a sectional test.

Incorrect example

You can either revise the notes or attempting a sectional test.

Interpretation

Place either and or so that the alternatives they introduce match grammatically. In a test, do not memorise this as an isolated sentence. Check both the logical relationship and the grammatical shape on each side. The correct example shows the pattern in context; compare it directly with the incorrect version and identify the exact word that must change.

Why it matters

Connectors determine both logic and parallel structure, which makes them useful exam traps.

Common exam trap

The two halves express the right idea but are not grammatically parallel.

How to spot it

Split the sentence at the connector and compare the grammatical form and logic on both sides.

3-step solving method

Name the logical relationship.
Split the two linked elements.
Make their grammatical forms parallel.

Why the incorrect example fails

The target structure requires this rule: Place either and or so that the alternatives they introduce match grammatically. In the incorrect version, the repair is to replace “attempting” with “attempt”. That is the exact edit a student should be able to justify in an error-spotting question.

Nuance and memory hook

A connector can be grammatically correct but logically wrong; check cause, contrast, condition and addition separately.

Same job, same grammatical shape.

Quick check

Without relying on what 'sounds right', explain which part of this sentence violates the rule: “You can either revise the notes or attempting a sectional test.”

Reveal quick check answer

Apply 'Either ... or' should join parallel alternatives: Place either and or so that the alternatives they introduce match grammatically.

Practice questions

Apply the rule in context

Which sentence is the better choice in standard exam-oriented English?

A. You can either revise the notes or attempting a sectional test.B. You can either revise the notes or attempt a sectional test.

Explain the error rather than guessing by sound

Why is this sentence problematic in the target rule? “You can either revise the notes or attempting a sectional test.”

A. If meaning is clear, parallel grammar does not matter.B. Although must be followed by but.C. Because must be paired with so.D. The target structure requires this rule: Place either and or so that the alternatives they introduce match grammatically. In the incorrect version, the repair is to replace “attempting” with “attempt”. That is the exact edit a student should be able to justify in an error-spotting question.

Rule 3 · G143

'Neither ... nor' should join parallel negatives

The two elements linked by neither and nor should be grammatically parallel.

Correct example

He neither guessed the answer nor skipped the question.

Incorrect example

He neither guessed the answer nor skipping the question.

Interpretation

The two elements linked by neither and nor should be grammatically parallel. In a test, do not memorise this as an isolated sentence. Check both the logical relationship and the grammatical shape on each side. The correct example shows the pattern in context; compare it directly with the incorrect version and identify the exact word that must change.

Why it matters

Connectors determine both logic and parallel structure, which makes them useful exam traps.

Common exam trap

The two halves express the right idea but are not grammatically parallel.

How to spot it

Split the sentence at the connector and compare the grammatical form and logic on both sides.

3-step solving method

Name the logical relationship.
Split the two linked elements.
Make their grammatical forms parallel.

Why the incorrect example fails

The target structure requires this rule: The two elements linked by neither and nor should be grammatically parallel. In the incorrect version, the repair is to replace “skipping” with “skipped”. That is the exact edit a student should be able to justify in an error-spotting question.

Nuance and memory hook

A connector can be grammatically correct but logically wrong; check cause, contrast, condition and addition separately.

Same job, same grammatical shape.

Quick check

Without relying on what 'sounds right', explain which part of this sentence violates the rule: “He neither guessed the answer nor skipping the question.”

Reveal quick check answer

Apply 'Neither ... nor' should join parallel negatives: The two elements linked by neither and nor should be grammatically parallel.

Practice questions

Apply the rule in context

Which sentence is the better choice in standard exam-oriented English?

A. He neither guessed the answer nor skipped the question.B. He neither guessed the answer nor skipping the question.

Explain the error rather than guessing by sound

Why is this sentence problematic in the target rule? “He neither guessed the answer nor skipping the question.”

A. Although must be followed by but.B. Because must be paired with so.C. The target structure requires this rule: The two elements linked by neither and nor should be grammatically parallel. In the incorrect version, the repair is to replace “skipping” with “skipped”. That is the exact edit a student should be able to justify in an error-spotting question.D. If meaning is clear, parallel grammar does not matter.

Rule 4 · G144

'Not only ... but also' should preserve parallelism

Match the grammatical form and scope on both sides of the correlative conjunction.

Correct example

The course improves not only speed but also accuracy.

Incorrect example

The course not only improves speed but also accuracy improvement.

Interpretation

Match the grammatical form and scope on both sides of the correlative conjunction. In a test, do not memorise this as an isolated sentence. Check both the logical relationship and the grammatical shape on each side. The correct example shows the pattern in context; compare it directly with the incorrect version and identify the exact word that must change.

Why it matters

Connectors determine both logic and parallel structure, which makes them useful exam traps.

Common exam trap

The two halves express the right idea but are not grammatically parallel.

How to spot it

Split the sentence at the connector and compare the grammatical form and logic on both sides.

3-step solving method

Name the logical relationship.
Split the two linked elements.
Make their grammatical forms parallel.

Why the incorrect example fails

The target structure requires this rule: Match the grammatical form and scope on both sides of the correlative conjunction. In the incorrect version, the repair is to add “improves”; remove “improves”; replace “accuracy improvement.” with “accuracy.”. That is the exact edit a student should be able to justify in an error-spotting question.

Nuance and memory hook

A connector can be grammatically correct but logically wrong; check cause, contrast, condition and addition separately.

Move ONLY and you can move the meaning.

Quick check

Without relying on what 'sounds right', explain which part of this sentence violates the rule: “The course not only improves speed but also accuracy improvement.”

Reveal quick check answer

Apply 'Not only ... but also' should preserve parallelism: Match the grammatical form and scope on both sides of the correlative conjunction.

Practice questions

Apply the rule in context

Which sentence is the better choice in standard exam-oriented English?

A. The course not only improves speed but also accuracy improvement.B. The course improves not only speed but also accuracy.

Explain the error rather than guessing by sound

Why is this sentence problematic in the target rule? “The course not only improves speed but also accuracy improvement.”

A. Because must be paired with so.B. The target structure requires this rule: Match the grammatical form and scope on both sides of the correlative conjunction. In the incorrect version, the repair is to add “improves”; remove “improves”; replace “accuracy improvement.” with “accuracy.”. That is the exact edit a student should be able to justify in an error-spotting question.C. If meaning is clear, parallel grammar does not matter.D. Although must be followed by but.

Rule 5 · G145

Do not normally pair 'although' with 'but' in the same clause structure

Although already marks concession, so standard formal English does not require but in the main clause.

Correct example

Although the set was difficult, we completed it.

Incorrect example

Although the set was difficult, but we completed it.

Interpretation

Although already marks concession, so standard formal English does not require but in the main clause. In a test, do not memorise this as an isolated sentence. Check both the logical relationship and the grammatical shape on each side. The correct example shows the pattern in context; compare it directly with the incorrect version and identify the exact word that must change.

Why it matters

Connectors determine both logic and parallel structure, which makes them useful exam traps.

Common exam trap

The two halves express the right idea but are not grammatically parallel.

How to spot it

Split the sentence at the connector and compare the grammatical form and logic on both sides.

3-step solving method

Name the logical relationship.
Split the two linked elements.
Make their grammatical forms parallel.

Why the incorrect example fails

The target structure requires this rule: Although already marks concession, so standard formal English does not require but in the main clause. In the incorrect version, the repair is to remove “but”. That is the exact edit a student should be able to justify in an error-spotting question.

Nuance and memory hook

A connector can be grammatically correct but logically wrong; check cause, contrast, condition and addition separately.

Although already carries the contrast; do not automatically add but.

Quick check

Without relying on what 'sounds right', explain which part of this sentence violates the rule: “Although the set was difficult, but we completed it.”

Reveal quick check answer

Apply Do not normally pair 'although' with 'but' in the same clause structure: Although already marks concession, so standard formal English does not require but in the main clause.

Practice questions

Apply the rule in context

Which sentence is the better choice in standard exam-oriented English?

A. Although the set was difficult, we completed it.B. Although the set was difficult, but we completed it.

Explain the error rather than guessing by sound

Why is this sentence problematic in the target rule? “Although the set was difficult, but we completed it.”

A. The target structure requires this rule: Although already marks concession, so standard formal English does not require but in the main clause. In the incorrect version, the repair is to remove “but”. That is the exact edit a student should be able to justify in an error-spotting question.B. If meaning is clear, parallel grammar does not matter.C. Although must be followed by but.D. Because must be paired with so.