A language is a dialect with an army and navy

"A language is a dialect with an army and navy", sometimes called the Weinreich witticism, is a mordant aphorism about the arbitrariness of the distinction between a dialect and a language. It was originally said in the context of the "social plight of Yiddish", and has been widely adopted as a shorthand for the importance of social and political conditions, rather than purely linguistic considerations, in defining the status of a language or dialect. The witticism was popularized by the sociolinguist and Yiddish scholar Max Weinreich, who heard it from a member of the audience at one of his lectures in the 1940s. A more scholarly approach to the problem of dialect versus language is the framework of abstand and ausbau languages.

Weinreich

This statement is usually attributed to Max Weinreich, a specialist in Yiddish linguistics, who expressed it in Yiddish:

אַ שפּראַך איז אַ דיאַלעקט מיט אַן אַרמיי און פֿלאָטa shprakh iz a dyalekt mit an armey un flot

The earliest known published source is Weinreich's article "Der YIVO un di problemen fun undzer tsayt" (דער ייִוואָ און די פּראָבלעמען פֿון אונדזער צײַט; lit. "The YIVO and the problems of our time"), originally presented as a speech on 5 January 1945 at the annual YIVO conference. Weinreich did not give an English version.

In the article, Weinreich presents this statement as a remark of an auditor at a lecture series given between 13 December 1943 and 12 June 1944:

A teacher at a Bronx high school once appeared among the auditors. He had come to America as a child and the entire time had never heard that Yiddish had a history and could also serve for higher matters. ...