Breakdown of Что касается обслуживания, то оно было великолепным.
оно
it
что
what
быть
to be
то
then (in that case)
Questions & Answers about Что касается обслуживания, то оно было великолепным.
Why is обслуживания in the Genitive case here?
It follows the phrase Что касается (As for / Regarding). This construction always forces the noun that comes after it into the Genitive case, because the verb касаться literally means 'to touch upon' and strictly requires the Genitive.
Do I always need to include то when using Что касается?
Yes, it is structurally required in standard Russian. When a sentence sets a topic with Что касается..., the second half (the main clause) begins with то to bridge the two ideas. You can think of it as saying: As for the service, then it was magnificent.
Why is the adjective великолепным in the Instrumental case rather than the Nominative (великолепное)?
When linking a subject to an adjective in the past tense using было (or был/была/были), Russian usually puts the adjective in the Instrumental case. This is the standard way to express descriptions, opinions, or temporary states in the past.
Why does the second part of the sentence use оно instead of это?
оно is a direct personal pronoun referring back to the specific neuter noun обслуживание (service). While using это (this) would be understood, using оно is much more natural here because it directly picks up the exact noun you just introduced as your topic.