system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do you properly use ";' and "-" in writing?
gpt
The semicolon is properly used in at least two ways.

First, it can be used to separate items in a list when some of those items contain commas. For example, a normal list would go like this: Apples, pears, bananas, and kiwi fruit. (Note: that last comma is not used by everyone. It is called the "Oxford comma", and people actually argue over whether or not it's necessary.)

But suppose the second item is "pears, but not Williams pears". Now it contains a comma; and so to make sure people can read the list easily, you have to write it like this: Apples; pears, but not Williams pears; bananas; and kiwi fruit.

Secondly, the semicolon is used to separate contact clauses. This is when you have two sentences and you want to join them into one sentence, but without using a conjunction. For example, if we start with these two sentences:

Mary likes beer. John prefers wine.

We can join them up with a conjunction:

Mary likes beer, but John prefers wine.

Or we can join them up with a semicolon:

Mary likes beer; John prefers wine.

Words like "however" are adverbs, not conjunctions, so if you want to use "however" to join these two sentences, you still need a semicolon:

Mary likes beer; however, John prefers wine.

How can you tell the difference? Well, you can move "however" next to the verb and it still makes sense:

Mary likes beer; John, however, prefers wine.

As for the hyphen, that's a much more complicated thing. Perhaps the most important use is to combine two words into one single concept, but it's much tickier to get this one right. In the sentence:

He was five years old.

we have "five" and "years" and "old" as three separate words; but in this sentence:

He was a five-year-old boy.

the three words are combined into a single unit, an adjective.