Tabitha Angel wrote:
How does one know when to use a semi-colon instead of a comma? I've always had trouble with this.
Here's the deal with semicolons:
They're not to be seen as anything close to a comma. Think of semicolons as a "swinging gate." I stole that term from a grammar book, but it was a good analogy. It's not a wall like a period, but it's not a gap in the wall like a comma either. Semicolons have a few uses, but the most common use is to separate two related but complete sentences.
"Judy went to the store. She bought eggs, milk, and bread." One could use a semicolon here instead of the period. Is it needed? No, not really. But its use wouldn't be wrong.
"I liked watching Infinity War; that one scene toward the end was intense." This is a better use of it, but I'd just use your judgment.
You can't use a semicolon in place of a comma, unless you're fixing a comma splice.
"Mitchell missed his motorcycle, it was his old man's."
This is a comma splice, meaning two independent clauses (complete sentences) have been smooshed together with a comma. It's just incorrect. To fix this, you can make the comma a period or a semicolon.
"Mitchell missed his motorcycle. It was his old man's."
"Mitchell missed his motorcycle; it was his old man's."
The subjects don't have to be the same, but the topic should be. If the first half of the sentence discusses beer, so should the second half (or at least another alcohol).
Both sides need to have complete sentences.
"Eric had an apetite; Jeanie, not so much."
This is incorrect because "Jeanie, not so much" is not a complete sentence. Fragments are wonderful things. I use them all the time. Don't use them with semicolons. Just use a period.
If you need anymore clarification, let me know!