The three uses
| Use | Wrong | Right | Why |
|---|---|---|---|
| Join two related sentences | The library was closed, we studied at home. | The library was closed; we studied at home. | Two complete sentences cannot be joined by a comma alone. A semicolon can join them. |
| Before however, therefore, moreover | It rained, however, the game went on. | It rained; however, the game went on. | However is not a joining word like but. The two sentences still need a semicolon or a period. |
| Lists whose items have commas | The tour visits Austin, Texas, Denver, Colorado, and Portland, Oregon. | The tour visits Austin, Texas; Denver, Colorado; and Portland, Oregon. | Semicolons show where each item ends when the items contain commas. |
When not to use one
| Mistake | Example | Fix |
|---|---|---|
| Before a part that is not a full sentence | Because it was late; we went home. | Because it was late, we went home. |
| To introduce a list | Bring three things; a pencil, a ruler, and a calculator. | Use a colon: Bring three things: a pencil, a ruler, and a calculator. |
| Between two unrelated sentences | My dog is brown; the test is on Friday. | Use two separate sentences. |
Worked examples
Example 1: fix a comma splice
Problem The movie ended, everyone clapped.
- Check each side: The movie ended and everyone clapped are both complete sentences.
- A comma alone cannot join them. Replace it with a semicolon, because the ideas are closely related.
Answer The movie ended; everyone clapped.
Example 2: however in the middle
Problem The forecast called for rain however the game went on as planned.
- Find the two sentences: The forecast called for rain and the game went on as planned.
- However starts the second sentence, so the semicolon goes before it and a comma goes after it.
Answer The forecast called for rain; however, the game went on as planned.
Example 3: a list with commas inside
Problem We met Ana, the captain, Leo, the goalie, and Sam, the coach.
- As written, it could be six people. Each item is really a name plus a role.
- Keep the comma inside each item, and put semicolons between the items.
Answer We met Ana, the captain; Leo, the goalie; and Sam, the coach.
Common mistakes and fixes
| Mistake | Fix |
|---|---|
| Using a semicolon where a colon belongs | If a list or explanation follows, and the second part is not a full sentence, use a colon. |
| Putting a comma before however between two sentences | Use a semicolon before however and a comma after it. |
| Using semicolons to sound smart | Use one only when it does one of its three jobs. A period is always fine. |
| Capitalizing the word after a semicolon | Lowercase it unless it is a proper noun or the word I. |
Practice
Five semicolon questions
Which sentence uses a semicolon correctly?
- Because the library was closed; we studied at home.
- The library was closed; we studied at home.
- The library; was closed, so we studied at home.
- We studied; at home because the library was closed.
Show answer
Answer: The library was closed; we studied at home.
Both sides are complete sentences, so the semicolon works. Because the library was closed cannot stand alone, and The library; was closed and We studied; at home split a sentence in the middle.
Which sentence is punctuated correctly?
- The forecast called for rain, however, the game went on.
- The forecast called for rain however; the game went on.
- The forecast called for rain; however, the game went on.
- The forecast called for rain, however the game went on.
Show answer
Answer: The forecast called for rain; however, the game went on.
However begins the second sentence, so use a semicolon before it and a comma after it. A comma before however makes a comma splice, and a semicolon after it attaches however to the wrong sentence.
Which sentence follows the rule for a list whose items contain commas?
- The tour visits Austin, Texas; Denver, Colorado; and Portland, Oregon.
- The tour visits Austin; Texas, Denver; Colorado, and Portland; Oregon.
- The tour visits Austin, Texas; Denver, Colorado, and Portland, Oregon.
- The tour visits; Austin, Texas, Denver, Colorado, and Portland, Oregon.
Show answer
Answer: The tour visits Austin, Texas; Denver, Colorado; and Portland, Oregon.
Each item is a city and state with a comma inside, so semicolons go between the items. Austin; Texas splits cities from their states, Colorado, and Portland puts a comma back between items, and visits; Austin puts a semicolon before the list.
Which sentence uses a semicolon incorrectly?
- I love to cook; my brother loves to eat.
- The road was icy; therefore, school was canceled.
- We met Ana, the captain; Leo, the goalie; and Sam, the coach.
- She packed three things; a tent, a stove, and a map.
Show answer
Answer: She packed three things; a tent, a stove, and a map.
A tent, a stove, and a map is a list, not a complete sentence, so it needs a colon. The other three use a semicolon for one of its three correct jobs.
What is the best way to fix this comma splice: The power went out, we lit candles.
- The power went out; we lit candles.
- The power went out we lit candles.
- The power; went out, we lit candles.
- The power went out, we, lit candles.
Show answer
Answer: The power went out; we lit candles.
Both sides are complete sentences, so a semicolon can join them. Removing the comma makes a run-on, and the other choices put punctuation inside the sentences.
Frequently asked questions
What is the difference between a semicolon and a colon?
A semicolon joins two complete sentences of equal weight. A colon comes after a complete sentence and points to what follows: a list, an example or an explanation. If what follows is a list or a single phrase, you want a colon, not a semicolon.
Can I use a semicolon with and or but?
Normally no: use a comma before and or but when they join two sentences. Some style guides allow a semicolon before and or but when the sentences are long and already full of commas, but that is rare. In school writing, the comma is the safe choice.
Do I capitalize after a semicolon?
No, unless the next word is a proper noun like Maria or the word I. A semicolon joins parts of one sentence, so the second part continues in lowercase.
Sources
- Purdue OWL, Commas vs. Semicolons, accessed October 1, 2026
- Purdue OWL, Semicolons, Colons, and Parentheses, accessed October 1, 2026
