のです
nodesu

Expression

1. the expectation is that ...; the reason is that ...; the fact is that ...; the explanation is that ...; it is that ...

りした くるま調子 ちょうし わるいのですが。
okarishita kurumano chōshiga warui nodesuga.
The car I rented from you has a problem.
ろく までは出発 しゅっぱつできないのです。
rokujimadewa shuppatsu dekinai nodesu.
I cannot start till six o'clock.
Other forms: