GRADE 9 English SCIENCE:FRICTION – WRITING:PUNCTUATION Notes
English Notes — Writing: Punctuation
Topic: Science — Friction (age 14, Kenya)
- Use correct punctuation when writing scientific sentences about friction.
- Recognise common punctuation errors and how to fix them.
- Write clear instructions and short reports on friction experiments.
- Full stop (.) — ends a sentence. Example: Friction opposes motion.
- Comma (,) — lists, separates clauses, or sets off extra information. Example: A rough surface, such as sandpaper, gives more friction.
- Question mark (?) — ends a question. Example: How does surface roughness affect friction?
- Exclamation mark (!) — shows strong feeling; rarely used in formal science writing. Example: What a large force of friction!
- Colon (:) — introduces a list, explanation or result. Example: Causes of friction: surface roughness, normal force, and material type.
- Semicolon (;) — joins closely related independent clauses. Example: Friction slows the block; it converts kinetic energy to heat.
- Parentheses ( ) — add extra information. Example: The reading increased to 2.5 N (newtons).
- Apostrophe (’) — shows possession or contractions. Use possession in reports, avoid contractions. Example: The object's mass was measured; do not write "it's" in formal reports.
- Quotation marks (" " or ‘ ’) — quote definitions or participants' remarks. Example: The teacher said, "Record the frictional force carefully."
- Hyphen (-) and dash (—) — hyphen for compound adjectives: low-friction surface. Use an en-dash or em-dash rarely in simple reports.
- Definition (full stop):
Friction is a force that opposes motion.
- Listing causes (commas and colon):
Causes of friction: surface roughness, normal force, and material type.
- Experiment instruction (imperative + full stop):
Place the block on the ramp and measure the frictional force using the spring balance.
- Adding extra info (parentheses):
The coefficient of friction (µ) depends on the materials.
- Joining ideas (semicolon):
The surface was rough; the block stopped quickly.
- Missing comma in a list
Wrong: Friction depends on surface roughness normal force and material.
Correct: Friction depends on surface roughness, normal force, and material. - Using contractions in formal reports
Wrong: It's clear that friction reduces speed.
Correct: It is clear that friction reduces speed. - Wrong sentence joins (comma splice)
Wrong: The block slid for 5 s, it stopped because of friction.
Correct: The block slid for 5 s; it stopped because of friction. - Apostrophe for plural (wrong)
Wrong: The object's were heavy.
Correct: The objects were heavy. (Use apostrophe only for possession: the object's mass)
- Keep sentences short and use full stops to separate ideas.
- Avoid exclamation marks — they are informal.
- Use colons to introduce results or lists: Result: friction decreased by 20%.
- Use parentheses for units and symbols: mass = 0.5 kg (kilograms)
- Start each sentence with a capital letter and end with the correct punctuation.
- friction opposes motion
- which surface has more friction wood or metal
- we measured the force it was 3.2 N
- the experiment showed two results increased friction decreased speed
- teacher said record your data carefully
Answers (click to view) ▼
- Friction opposes motion.
- Which surface has more friction — wood or metal?
- We measured the force; it was 3.2 N.
- The experiment showed two results: increased friction and decreased speed.
- The teacher said, "Record your data carefully."
🔬 Sentence → PUNCTUATION → Clear meaning
Example: "Block on table" ➜ "The block is on the table." (adds verb + full stop = complete sentence)