Quick Answer
It depends on the guide. Chicago capitalizes "So", because CMOS 8.159 lowercases five coordinating conjunctions (and, but, for, or, nor) and "so" is not one of them. MLA, APA, and AP keep "so" lowercase mid-title. Every guide capitalizes "So" when it is the first word, the last word, or the word directly after a colon.
You can also paste any title into the free title case converter at the top of the page to apply these rules automatically.
When you're prepping a title, whether it's for an article, essay, or book, knowing how to capitalize words correctly is key to looking polished and professional. Confusion often swirls around small words like 'so'. Let's set the record straight: In most major title capitalization styles, 'so' is not capitalized because it's a conjunction.
Title Capitalization Rules
In title capitalization, it's the type of word that matters. Major title styles like Chicago, MLA, APA, and AP have similar rules for these small words. Conjunctions, articles, and short prepositions (usually with fewer than four letters) stay in lowercase. On the other hand, the first and last words of the title get a capital, no matter what parts of speech they are.
The Case of 'So'
'So' is often used to connect two ideas, which makes it a conjunction. Because it's also just two letters, it falls under the rule of not capitalizing short conjunctions. For example:
Life Is so Beautiful follows the rule because 'so' is not the first or last word and it's not a major word in the title. On the flip side, in titles like So Much to Explore, 'So' is the first word and thus, gets a capital letter.
Always Check Your Style Guide
While Chicago, MLA, APA, and AP agree on this rule, it's always wise to double-check the guidelines specified by the style you're required to use. Different publications or teachers might have their own preferences that slightly twist standard practices. But when in doubt, remember that for 'so', keep it simple and keep it lowercase.
when you write a title, remember capitalization rules can vary depending on the style guide. The Chicago Manual of Style and MLA require all "major" words to be capitalized, which means the word 'so' is typically lowercase in a title unless it's the first or last word. APA says to capitalize words with four or more letters, so 'so' stays lowercase. AP style, focusing on simplicity, would also keep 'so' in lowercase unless it starts the title. Keep these rules in mind to polish your titles and make sure your writing looks its best. Thank you for reading and good luck with your writing!
For a deeper breakdown of how each guide handles capitalization, see the title case styles guide.
