Breakdown of Он возвращался с работы поздно.
он
he / it (for a masculine noun) / it (for a neuter noun)
работа
work, job
поздно
late
возвращаться
to return, to come back
Questions & Answers about Он возвращался с работы поздно.
Since this lesson is about passive verbs with '-ся', is this sentence passive?
No, he is actively returning! While adding -ся to an imperfective verb can create a passive meaning (like дом строится - 'the house is being built'), it is also used to make an action affect the subject itself. Возвращать means 'to return [an object]', so возвращаться means 'to return [oneself]' or simply 'to come back'.
Why do we use 'с' (from) here instead of 'из'?
This is a great reminder of the paired prepositions of motion. Because you go to work using на (на работу), you must use с when returning from it. If you were returning from a place that takes в (like в школу - to school), you would use из (из школы).
Why does the translation say 'used to come back' instead of just 'came back'?
The verb возвращался is imperfective. In the past tense, imperfective verbs are often used to describe habitual or repeated actions. If this were a single, one-time completed event ('He came back late last night'), Russian would use the perfective verb вернулся.