Chicago in-text citation and footnotes
Chicago gives you two systems: author–date brackets for the sciences, or numbered footnotes for history and the humanities. Check your assignment brief, then build either one here.
Chicago author-date generator
Your Chicago 18 parenthetical citation
(Nguyen 2021, 14)
Where it goes in a sentence
Sleep loss impairs next-day recall (Nguyen 2021, 14).
Why it looks like this: Chicago author-date: no comma between author and year; a comma before the page.
Chicago author-date in-text citations
Format: (Author Year, page), with no comma between author and year: (Nguyen 2021, 14). Two authors: (Nguyen and Ortiz 2021). Three or more: (Nguyen et al. 2021). Several works: (Lee 2019; Nguyen 2021).
Chicago notes-bibliography: footnotes
In the notes system, a superscript number goes in your sentence, normally after the punctuation at the end of the clause, except a dash.1 The note at the foot of the page gives the source. The first time you cite a work, give the full note; after that, use a short note.
Chicago footnote generator
First note
1 Maya Nguyen, Sleep and the Student Brain: What the Evidence Shows (Chicago: University of Chicago Press, 2021), 14.
Later notes (shortened)
2 Nguyen, Sleep and the Student, 14.
Footnotes or endnotes?
Both follow the same format. Footnotes sit at the bottom of each page; endnotes are collected at the end of the paper. Footnotes are easier for markers to check, so most instructors prefer them unless told otherwise.
Repeating a source: short notes and ibid.
The Chicago Manual of Style, 18th edition, prefers a shortened note (author, short title, page) even when the same source is cited twice in a row. Ibid. is still allowed. Step through a real sequence on the ibid. explainer.