Baffled by semicolons? Not sure when to use them? Won’t a comma do instead?
Think of the semicolon as a full stop (period) combined with a comma. It is not quite a full stop and not quite a comma. You might use it when the next clause is related in subject or idea, but not so unrelated as to warrant a full stop.
In short, a semicolon combines two or more clauses, that are related in subject or idea and could be written alternatively as either one sentence or two separate ones.
Clause/sentence 1: I bought these potatoes in the local farm shop
Clause/sentence 2: They make lovely creamed potato
As two sentences: I bought these potatoes in the local farm shop. They make lovely creamed potato.
As one sentence (using the conjunction and – you could use a comma instead of and): I bought these potatoes in the local farm shop and they make lovely creamed potato.
In the first example above we have two related clauses split apart. It would do but it’s not ideal for clarity In the second example the conjunction joins the two clauses, but sounds awkward, as if the second clause was going to be part of a list.
One sentence but using a semicolon: I bought these potatoes in the local farm shop; they make lovely creamed potato.
I have combined two of the ideas above (the comma and the full stop) to join them into one sentence that makes the meaning clear. Now it sounds more like these potatoes make a lovely dish.
When not to use a semicolon
I bought these potatoes in the local farm shop; my husband’s feet are worse.
The two clauses are unrelated and should be broken down into two separate sentences (they are so unrelated they probably deserve separate paragraphs).
Semicolons can be used to replace the conjunctions and, nor, yet, but, so, for where these are used to join two or more clauses, or related ideas.
Lists and semicolons
Semicolons are often used in lists when each item in the list has a sub-item, for example a list of town names and the county they are in.
We have a number of towns representing different counties: Chelmsford, Essex; Reading, Berkshire; and Cromer, Norfolk.
If it had been written using only commas it would read as a list of six places with commas separating each item, like this:
We have a number of towns representing different counties: Chelmsford, Essex, Reading, Berkshire, and Cromer, Norfolk.
If you know which county each town is in you’re up on your geography, but if you don’t know there’s a problem with this sentence. The semicolons, however, make it clear that we are talking about three places and where they are.
Semicolons and listing semicolons separate parts of a sentence but also keep them together, so make sure you’re making sense.
Don’t overdo it
Don’t overdo it with the semicolons, especially now you know how to use them. Too many in a sentence can make it seem like an endless list and too many sentences with semicolons are unnecessary.