In addition, correct punctuation in an English-language sentence can be determined by the language variant (British or American) or the chosen style of text formatting (APA, Harvard, etc.). For example, in many American English styles (APA style, for example), a serial comma is used before the last of the enumerated words (... a, b, and d). In addition, in the APA style, quotation marks are placed after the punctuation mark, not before it: “We analyzed graphs, curves, and figures.”