Punctuation inside sentences and deliberate non-punctuation
Use punctuation to show structure, including lists, coordination, supplementary information and essential elements.
What you will tackle
- Punctuate coordinated clauses and series
- Distinguish coordinating conjunctions from conjunctive adverbs
- Pair commas, dashes or parentheses around supplementary material
- Use colons after complete clauses
- Recognise when no punctuation belongs
Find the sentence's core
Supplementary material can be removed while leaving the central structure intact. ‘The river, which flooded in May, is now calm’ needs both commas. Essential information identifying which person or thing is meant may not take such punctuation. Do not place a comma between a subject and its verb or a verb and its required object.
Match the mark to the structure
A colon may introduce a list or explanation after a complete clause: ‘We packed three items: rope, water and maps.’ A coordinating conjunction can join two clauses with a preceding comma; a conjunctive adverb usually needs a sentence boundary or semicolon before it. List punctuation should keep equivalent elements clear.
Build your notes, then practise
Work on paper before opening an explanation. Guided tasks provide a starting point; independent tasks remove the scaffolding; application tasks ask you to justify a method or interpretation in context.
Guided practice
Guided 1
Punctuate ‘The archive which opened in 1972 holds letters photographs and maps’ assuming the opening date is extra information. Explain both pairs and the series.
Show a starting hint
Remove the supplementary phrase temporarily to see the core.
Compare with the explained answer
- The core is ‘The archive holds letters, photographs and maps.’
- Add paired commas around ‘which opened in 1972’.
- Separate series elements; a serial comma before and is also acceptable.
Answer / response criteria: ‘The archive, which opened in 1972, holds letters, photographs and maps.’
Guided 2
Rewrite ‘The river, which flooded in May, is now calm’ using paired dashes and then parentheses for the supplementary clause. Identify the unchanged core sentence.
Compare with the explained answer
- Dashes can bracket ‘which flooded in May’ on both sides.
- Parentheses can bracket the same supplementary material.
- The core stays ‘The river is now calm.’
Answer / response criteria: ‘The river—which flooded in May—is now calm.’ ‘The river (which flooded in May) is now calm.’
Independent practice
Independent 1
Correct or accept: ‘The students, completed the survey.’ ‘They collected: samples and photographs.’ ‘The goal was clear: reduce waste.’ Explain the needed absence or presence of punctuation.
Compare with the explained answer
- Remove the comma between students and completed.
- Remove the colon separating collected from its direct object.
- The third colon follows a complete clause and introduces an explanation.
Answer / response criteria: ‘The students completed the survey.’ ‘They collected samples and photographs.’ The third sentence is correct.
Independent 2
Repair the mismatched supplementary punctuation: ‘The guide—an experienced climber, checked the route.’ Give a dash version and a comma version.
Compare with the explained answer
- The supplementary phrase begins at an experienced climber.
- The same bracketing structure must close before checked.
- Use two dashes or two commas, retaining the core subject and verb.
Answer / response criteria: ‘The guide—an experienced climber—checked the route.’ ‘The guide, an experienced climber, checked the route.’
Application practice
Application 1
Edit for clarity: ‘The first design was light, however, it was fragile and the second design which used steel was heavier.’ Treat the steel phrase as supplementary and preserve the contrast.
Compare with the explained answer
- Replace the splice before however with a semicolon or period.
- Use a comma before and when joining the following two independent clauses, or split them into sentences.
- Pair commas around the supplementary steel phrase.
Answer / response criteria: One valid revision: ‘The first design was light; however, it was fragile. The second design, which used steel, was heavier.’
Application 2
A report needs a low-emphasis note identifying a measurement as an estimate. Add it parenthetically to ‘The distance was 15 km’ without separating the subject from its verb with an unmatched mark.
Compare with the explained answer
- Keep the complete core ‘The distance was 15 km.’
- Place a paired note such as ‘(an estimate)’ after the measurement.
- The punctuation closes the supplementary note while preserving the clause.
Answer / response criteria: ‘The distance was 15 km (an estimate).’
What can you explain now?
A report needs a low-emphasis note identifying a measurement as an estimate. Add it parenthetically to ‘The distance was 15 km’ without separating the subject from its verb with an unmatched mark.
Compare with the explanation
‘The distance was 15 km (an estimate).’
Explain the reasoning before comparing. This review records your self-assessment rather than an official score or mastery decision.
After trying it yourself, choose your next review. This is your self-assessment.
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Source and review status
Coverage follows the named requirements and examples in the 2026–2027 ACT test guide and subject descriptions. That guide explicitly does not list every possible topic. The broader coded College and Career Readiness Standards are also mapped to conceptual teaching and practice; this does not calibrate a learner to a score band. The separate scientific-background context list and reading-complexity rubric have their own stated limits.
Original teaching and explained self-check practice are available. Specialist review and difficulty calibration remain pending. Essays require self-check or teacher review and are not automatically marked or awarded official scores.
Official source specification / guide