How it works
Punctuation should make grammatical and logical structure visible. Use commas after introductory dependent clauses and around nonessential information, but not automatically wherever speech pauses. A colon can introduce a list or explanation after a complete clause. A semicolon joins closely related independent clauses or separates complex list items. Lists should use parallel forms and consistent punctuation. Proofread by identifying the structure first; a punctuation mark cannot repair an incomplete or poorly connected sentence by itself.
Patterns
Introductory clause
When/If/Although dependent clause, independent clause.
Mark the boundary between context and main statement.
Explanatory colon
Complete clause: explanation or list.
Signal that what follows develops the complete statement before it.
Before and after
- Before
- If the clinic expects a long wait I will collect the order and return.
- After
- If the clinic expects a long wait, I will collect the order and return.
- Why
- The comma marks the end of the introductory condition.
- Before
- Please bring: your card, the code, and identification.
- After
- Please bring three items: your card, the code, and identification.
- Why
- A complete clause now appears before the colon.
Practice
- Add punctuation to six introductory-clause sentences.
- Write three complete clauses followed by explanatory colons.
- Edit one list for parallel grammar and consistent marks.
Show the answer key
- Introductory dependent clauses are followed by commas in the target examples.
- Text before each colon must be grammatically complete.
- List items should share the same grammatical form.
