A period doesn’t require that the preceding clause and following clause are closely related. A semicolon implies relation; they are closely related complete clauses. A comma doesn’t require they are complete clauses, but necessarily related as parts of the same sentence and requires a conjunction between clauses you connect with it.

It sounds like you’ve got it. It separates two clauses, preferably not more; it works like a soft period.

Misuse is throwing thirteen in a row as a substitute for periods. Or worse, using it in lieu of commas, parentheticals, and footnotes simultaneously. Here you go, Tristram Shandy, good luck keeping this whole page in your head at once.

writingcommons.org/section/grammar/…/semicolons/

Explains it nicely. Linking closely related independent clauses is the most common way I use them.

You’ve already gotten the formal and, thus, best answer.

However, formal writing isn’t the only writing the same way formal speaking isn’t the only speaking.

A semicolon can serve to break up sentences into segments when it’s really long and contains commas out the wazoo already. It makes such things more readable.

I’ve also seen them used informally to indicate a longer pause in speech than a comma, but not as long as that indicated by a period.

Think of a period as when someone would pause, take a breath, then start again. A comma is just the pause; a semicolon would be the kind of quick breath you use when commanding, singing, or otherwise using your voice for an extended span where stopping for a full breath isn’t desired.

Again those are informal uses, but they do exist and can become a formal use given enough time and adoption. The problem is that until that happens, it’s confusing for anyone that reads them that is more familiar with formal writing. So, as a communication tool, using them informally can be ineffective. Kind of a tossup tbh.

A semicolon is like a comma or colon in that it clarifies the proceeding part of the sentence, and is a complete sentence itself.

A semicolon is like a comma or colon in that it clarifies the proceeding part of the sentence: a complete sentence in itself.

A semicolon is like a comma or colon in that it clarifies the proceeding part of the sentence; it is a complete sentence itself.

At the end of function calls

How to use a semicolon - The Oatmeal theoatmeal.com/comics/semicolon

An elegant example that I like is “TL;DR” (or “Too Long; Didn’t Read”). Each of those clauses could stand independently, with a full stop between them, but the semicolon makes it clearer that the reason why one wouldn’t read something is directly related to it being too long.

You can also use it to separate items in a list when the items themselves contain commas, eg:

Attendees included Michael Simps, chair of the oversight committee; Allison Charles, VP of outreach; and Yasmin Blort, a local activist.

You’ve got a good range of answers here, so I’ll give some indirect advice instead. When I started making a concerted effort to improve my own writing, I found that reading more helped to consolidate my growth, especially when I was doing it mindfully (such as finding a passage of text that I liked and trying to annotate it with what I personally liked about it).

Some authors don’t use semicolons at all, but if you do find a good piece of writing that has some use of semicolons, it can be useful to look at how often they use them (“good” can refer to either writing that you personally appreciate, or writing that is widely held to be high quality, such as by respected authors. Ideally stick to properly published works, because online comments, blog posts etc. are less likely to adhere to grammatical conventions (not inherently a bad thing, just makes them limited as a learning tool)).

You’ll probably find that there are very few semicolons, because to use them properly means using them in moderation. If you find a text that has one semicolon on an entire page of writing, try looking over other clauses on that page and find other places where the author could have used a semicolon. Then ask yourself why these feel distinct from the place where a semicolon was used, and why the author might have chosen this particular place from a semicolon.

This comment brought to you by a chronic overuser of semicolons. All should applaud me for not using any semicolons in this comment.

A semicolon is used for connecting a supporting idea that is also a complete sentence rather than a dependent clause; this serves to support the sentence before the semicolon. The second sentence is connected with the semicolon to show that it is supporting the main sentence and shouldn’t be taken alone.

A colon is used when the supporting element is not a complete sentence: lists, examples, dependent clauses that cannot be parsed alone, etc.