Colons aren’t frequently abused as a punctuation, not like commas or exclamation points typically are. With that said, some situations will call for plugging them into your text and it’s best you know the rules before going to work.
- When in doubt, start the statement after the colon with a lowercase letter. In fact, many people just avoid uppercase forms altogether, regardless of whether the following line is a sentence or a fragment. Do note that classic English form requires capitalizing under certain conditions.
- For lists and other fragments, starting with a lowercase letter is the default way to lay it out. A dash is an equally acceptable replacement for some situations, especially for less formal situations.
- When a colon is used to introduced a complete sentence, the traditional rule is to start it in uppercase form. Substituting with a dash usually isn’t acceptable.
- When a colon is followed by a complete sentence but doesn’t introduce it, starting in lowercase is the norm. A dash can also be used as a replacement, although a colon is almost always the better choice.
I’ve seen several instances of a colon being used to introduce multiple sentences. While not entirely incorrect (even your grammar software will approve it), it’s very confusing and is decidedly bad form. Try avoiding it at all costs.
