The Hopi time controversy is the academic debate about how the Hopi language grammaticalizes the concept of time, and about whether the differences between the ways the English and Hopi languages describe time are an example of linguistic relativity or not. In popular discourse the debate is often framed as a question about whether the Hopi "have a concept of time", despite it now being well established that they do.
The debate originated in the 1940s when American linguist Benjamin Lee Whorf argued that the Hopi conceptualized time differently from the Standard Average European speaker, and that this difference correlated with grammatical differences between the languages. Whorf argued that Hopi has "no words, grammatical forms, construction or expressions that refer directly to what we call 'time'", and concluded that the Hopi had "no general notion or intuition of time as a smooth flowing continuum in which everything in the universe proceeds at equal rate, out of a future, through the present, into a past". Whorf used the Hopi concept of time as a primary example of his concept of linguistic relativity, which posits that the way in which individual languages encode information about the world, influences and correlates with the cultural world view of the speakers. Whorf's relativist views fell out of favor in linguistics and anthropology in the 1960s, but Whorf's statement lived on in the popular literature often in the form of an urban myth that "the Hopi have no concept of time". In 1983 linguist Ekkehart Malotki published a 600-page study of the grammar of time in the Hopi language, concluding that he had finally refuted Whorf's claims about the language. Malotki's treatise gave hundreds of examples of Hopi words and grammatical forms referring to temporal relations. Malotki's central claim was that the Hopi do indeed conceptualize time as structured in terms of an ego-centered spatial progression from past, through present into the future. He also demonstrated that the Hopi language grammaticalizes tense using a distinction between future and non-future tenses, as opposed to the English tense system, which is usually analyzed as being based on a past/non-past distinction. Many took Malotki's work as the final nail in the coffin of the linguistic relativity hypothesis. Linguist and specialist in the linguistic typology of tense Bernard Comrie concluded that "Malotki's presentation and argumentation are devastating". Psychologist Steven Pinker, a well-known critic of Whorf and the concept of linguistic relativity, accepted Malotki's claims as having demonstrated Whorf's complete ineptitude as a linguist.