The legitimate plural forms of non sequitur include the Anglicised non sequiturs and the Classical non sequuntur; non sequituri is also attested, but is rare, non-standard, and misformed.

Is there a plural of non sequitur?

In Latin, non sequitur is a sentence, not a noun. It consists of non "not" and the verb sequitur "it follows". As a sentence, it cannot be made plural by adding the nominative plural suffix for second declension nouns. As an English noun, it has the English plural non sequiturs.

Is non sequitur two words or one?

A non sequitur (English: /nɒn ˈsɛkwɪtər/ non SEK-wit-ər, Classical Latin: [noːn ˈsɛkᶣɪtʊr]; "it does not follow") is a conversational literary device, often used for comedic purposes.