Learn Polish: Pracuję na pełny etat w banku.

The word etat refers to a job position, a post, or a staff slot at a company. The set phrase na pełny etat literally means on a full position. It is the standard way to express working full-time in Polish.

Why is pełny etat in the accusative case here instead of the locative, since it follows the preposition na?

The preposition na takes the locative case when describing a physical location (like on a desk), but it takes the accusative case when describing a state, condition, or arrangement, such as the terms of your employment here.

Why is it w banku with an -u ending instead of the usual -ie for the locative case?

Masculine inanimate nouns typically take the -ie ending in the locative case, which triggers a consonant mutation. However, nouns ending in a velar consonant like -k, -g, or -ch (such as bank) take the -u ending instead to avoid awkward sound changes. Thus, we say w banku.

If na pełny etat means full-time, how would I change this sentence to say I work part-time?