Mastronarde, 2nd edition, unit 12, example

[hlawson38]

This example from Mastronarde is meant to illustrate the usage of the pronoun αὐτόσ

τὰ βιβλία ἦν αὐτοῦ τοῦ διδασκάλου, οὺ τοῦ ποιητοῦ.

The books belonged to the teacher himself, not to the poet.

What I don't understand is the third word: ἦν.

I don't even know what part of speech it is. And especially I don't know if it performs a grammatical function in relation to the pronoun αὐτόσ.

[bedwere]

Imperfect of εἰμί

[hlawson38]

Imperfect of εἰμί

Thanks bedwere, I'm still limited to the present tense of εἰμί .

[jk0592]

Also, be aware that a neuter plural takes the singular verb.

[hlawson38]

Many thanks, Jean, I must remember that neuter plural nouns agree with singular verbs.