With a handful of exceptions that I’ll get to in later posts (or you can just read section 13.7 in the Chicago Manual), quotations should stick to the original wording, spelling, capitalization, and punctuation of the source. When I find mistakes in quotations, often it’s just a case of incorrect copying on the author’s part, but sometimes it’s because the author ran spellcheck, grammar check, or find-and-replace on the document and accidentally applied changes to a quotation that was originally copied correctly.
Some situations where this is likely to occur if you’re not careful:
- US vs. UK spelling and grammar (-or/-our and -ize/-ise words, singular vs. plural verbs with collective nouns, etc.)
- Capitalized vs. lowercase deity pronouns in writing on Christian topics, and other examples of reverential capitalization
- Archaic spelling, grammar, or usage (e.g., in quoting the King James Bible)
- Identity terms that some writers capitalize and others don’t, or that may be capitalized or lowercase in different contexts (e.g., Black, Indigenous, Deaf)
- Other terms whose preferred form is contested and/or changing (e.g., hip-hop vs. hip hop, anti-Semitism vs. antisemitism)
- Different transliterations of names and terms (for example, if you’re writing about Sergei Prokofiev and quote an older source that refers to him as Prokofieff)
Although it takes longer, I recommend applying spellcheck and find-and-replace changes one at a time instead of globally, checking each suggested change to make sure it’s not incorrectly altering a quote.