Questions & Answers about Мы приехали поздним вечером.
Why are поздним and вечером in the Instrumental case here?
In Russian, to say that something happens 'in the morning,' 'in the afternoon,' or 'in the evening,' you use the Instrumental case of those nouns (утром, днём, вечером). Because we are adding the adjective поздний (late), it also has to be in the Instrumental case to match: поздним вечером.
The current lesson is about exact clock times. If I added an exact time like 'at 7:10 PM', would I still use the Instrumental вечером?
No. When you give an exact clock time and want to specify 'PM' or 'in the evening,' you use the Genitive case: семь часов десять минут вечера. You only use the Instrumental вечером when talking about 'in the evening' as a general time period.
Why did we use the perfective verb приехали instead of the imperfective приезжали?
We use the perfective приехали because the arrival is a completed, one-time action with a clear result. We successfully reached our destination late in the evening.