 In spite of his blind spot about tenses, al-Fārābī’s comments on verbs in Arabic contain some of his best linguistic insights. For example, he notes that since tenses are needed only for talking about accidents, one should not expect to find a verb whose primary concept is a permanent notion such as “human” (insān). He tests this by constructing a verb from “human”, namely ta’annasa. By the rules of Arabic, one would understand it to signify something with a temporal feature, namely “becoming a human” ([Commentary on De Interpretatione] 34.4–9). Al-Fārābī also uses a quite subtle linguistic argument to show that Arabic has a word that can express pure tense without copula or primary concept. This is the word kāna, as in “Zayd was walking”, zaydun kāna yamshī. We can see that there is no copula in kāna, he tells us, because “Zayd is walking”, zaydun yamshī, already contains a copula in the verb yamshī ([Commentary on De Interpretatione] 42.6–18). We even find the beginnings of an analysis of the structure of events in al-Fārābī’s discussion of how the present tense can signify either a point of time or an interval ([Commentary on De Interpretatione] 40.3–41.18). 