Breakdown of По дороге домой он всегда заезжает на заправку.
он
he / it (for a masculine noun) / it (for a neuter noun)
всегда
always
на
on, at / by (transport) / to (a place) / to (in answer to)
домой
home
Questions & Answers about По дороге домой он всегда заезжает на заправку.
The lesson is about заходить, so why does this sentence use заезжает?
Both verbs use the prefix за-, which means to make a short detour or "drop in" somewhere on your way. You use заходить when walking, but since stopping at a gas station implies driving, we use the vehicle-based root -езжать instead.
Why is the imperfective verb заезжает used here instead of the perfective заедет?
The word всегда (always) tells us this is a repeated, regular habit. For repeated or ongoing actions, Russian requires the imperfective aspect.
Why do we say на заправку instead of в заправку?
A gas station (заправка) is thought of as an open area or surface rather than an enclosed building, so it pairs with на instead of в. Because it is the destination of his motion, it takes the accusative case (заправку).
Why does the sentence use домой instead of дома?
Домой means "(to) home" as a direction of movement, while дома means "(at) home" as a stationary location. Since he is actively traveling towards his house, we use the directional word.
Why is дороге in the dative case?