Learn Finnish: Bussi on taas myöhässä.

In Finnish, temporary states of being are frequently expressed using local cases. Myöhässä literally translates to 'in late.' While this sentence doesn't feature a two-part absolute phrase of state (like kädet taskussa), it relies on the exact same grammatical logic taught in this lesson: using a local case ending to establish a state. You see this in other time states too, like ajoissa (on time).

Why couldn't I say Bussi on taas myöhään?

Myöhässä specifically means 'delayed' or 'behind schedule.' Myöhään means 'late in the day' or 'late at night.' If you said Bussi on taas myöhään, it would sound like you are trying to say the bus exists late at night. To say it operates late into the night, you would use a different verb: Bussi kulkee myöhään.

Could I use the adjective myöhäinen instead of myöhässä?

No. Myöhäinen is an adjective that describes an inherent characteristic, such as myöhäinen ilta (a late evening). Because the bus being delayed is a temporary condition rather than an inherent trait of the bus itself, Finnish requires the state adverbial myöhässä.

Does moving taas change the tone of this sentence?