Breakdown of Onun hakkında hiçbir anons duymadık.
o
that / he / she / it
duymak
to hear
hiçbir
no / not any (determiner)
hakkında
about, concerning
Questions & Answers about Onun hakkında hiçbir anons duymadık.
Why is it onun hakkında instead of just o hakkında?
When using the postposition hakkında (about) with a pronoun, the pronoun must take the genitive (possessive) case. That is why o (it) becomes onun (its). Regular nouns do not need this change, so you can just say anons hakkında (about the announcement).
Could I use the other postpositions from this lesson, like ile ilgili or -A dair, in this sentence?
Yes, but you have to change the pronoun to match the grammar of those postpositions. You could say onunla ilgili (attaching ile to onun) or ona dair (adding the dative -a to o). Both would still mean 'about it' or 'regarding it' here.
Why is the verb duymadık negative if hiçbir already translates to 'no' in English?
In Turkish, words like hiçbir (not any / no) and hiç (never / none) must be paired with a negative verb. While English avoids double negatives, Turkish requires them here. Literally, this sentence translates as 'We did not hear any announcement.'
Is hiçbir always written as one word?