You may write the most brilliant story with the most sympathetic characters, but if your manuscript is full of spelling errors and typos, you will struggle to find readers.
☐ Spelling is correct.
English spelling is notoriously difficult. It is rarely phonetic, as Spanish is, and is not consistent, as French is. Honestly, the only way those kids who win the spelling bees do it is by memorizing. If you’re not entering a spelling bee, just use a good dictionary. The folks at The Chicago Manual of Style recommend Merriam-Webster’s. The abridged version is free, and will serve most of your needs. An unabridged version is available by subscription if you think it necessary.
A less authoritative but still fun source is OneLook, which searches over a thousand dictionaries. It’s useful for highly specialized terms and slang that hasn’t made it into traditional dictionaries yet.
Spelling is often contingent upon which stylebook you’re using. For example, whether OK is spelled with two letters or four will depend on whether you’re using the Associated Press Stylebook (OK) or Christian Writer’s Manual of Style (okay). Novel-writers will usually follow Chicago style, which actually doesn’t specify a preference on OK.
Do not trust spellcheck! It is notoriously stupid, such as when, in a novel about an artist, it wanted me to change a reference to the great Renaissance fantasist to “Hieronymus Borscht.”
Ever since “Cupertino” was first substituted for “cooperation,” the former has been used to describe the kind of autocorrect errors people make fun of on Facebook. Don’t let your manuscript be filled with Cupertinos. Check your spelling against a real dictionary. Spellcheck won’t save you if you type “manger” instead of “manager” or if you leave the L out of public, so proofread closely.
Does spelling really count? Do people really care if there’s a Cupertino or two? If the story is great, won’t people overlook a few typos?
No, they won’t. If you are seeking traditional publication, acquisition editors can and will reject your manuscript on the basis of “too many typos.” They are inundated with ten times as many manuscripts as they can publish, so they will prefer to work with the writers who pay attention to this kind of detail.
As for readers, if you think they’ll forgive in a self-published book, go on Amazon and see how many one- and two-star reviews criticize books for having too many typos.