Breakdown of Мы говорили об этих навыках на собеседовании.
мы
we
этот
this [f: эта, n: это]
говорить
to speak, to talk
на
on, at / by (transport) / to (a place) / to (in answer to)
Questions & Answers about Мы говорили об этих навыках на собеседовании.
Why is it об instead of just о?
The preposition о (about) changes to об when the next word starts with a vowel. Here, the next word is этих (these), which starts with the vowel э, so we use об to make it flow better when speaking.
What case are этих навыках in?
They are in the prepositional case because they follow the preposition об (about). The dictionary forms are эти (these) and навыки (skills). In the prepositional plural, эти changes to этих, and plural nouns change to end in -ах or -ях (hence, навыках).
Why does собеседовании end in -ии instead of the usual prepositional ending -е?
The dictionary form of the word is собеседование (interview), which is a neuter noun ending in -ие. A special rule for nouns ending in -ие, -ия, or -ий is that their prepositional case ending is -и instead of -е. So, -ие becomes -ии.
Why do we use на for 'at the interview' instead of в?