Learn Hardcore Finnish: Sunnuntaisin bussi on usein myöhässä.

The ending -sin is the adessive plural form of sunnuntai (“Sunday”). In Finnish it’s used adverbially to express habitual actions: sunnuntaisin = “on Sundays” (i.e. every Sunday).

Why is bussi singular instead of plural?

Even though we’re speaking about buses in general, Finnish often uses the singular to talk about a recurring or generic thing. Here bussi (nominative singular) refers to “the bus service” or “a typical bus.”

Why isn’t there an article like the or a before bussi?

Finnish has no definite or indefinite articles. A bare noun such as bussi can be translated as “a bus” or “the bus” depending on context. In this sentence it’s understood generically.

What case is myöhässä, and how does it convey “late”?

Myöhässä is the essive form of the adjective myöhässä (historically from myöhä), functioning adverbially to mean “in a state of delay.” Combined with the verb olla (“to be”), olla myöhässä = “to be late.”

Why is usein placed before myöhässä rather than elsewhere?

As an adverb of frequency, usein (“often”) typically appears before the main verb or verb phrase. Here the neutral order is bussi on usein myöhässä. Finnish word order is flexible, but this placement is most common.

Why does the sentence begin with Sunnuntaisin?

Fronting the time expression sunnuntaisin (“on Sundays”) emphasizes when something happens. A neutral alternative is Bussi on usein myöhässä sunnuntaisin, but both word orders are correct.

Could you use sunnuntaina instead of sunnuntaisin?

Yes, but they differ in meaning:
• sunnuntaina is adessive singular = “on (one specific) Sunday.”
• sunnuntaisin is adessive plural = “on Sundays” (habitually, every Sunday).

What’s a literal breakdown of each word in the sentence?

• Sunnuntaisin = “on Sundays” (adessive plural, habitual)
• bussi = “bus” (nominative singular)
• on = “is”
• usein = “often”
• myöhässä = “late” / “in delay” (essive)
So literally: “On Sundays bus is often late.”