sunnuntaisin

Sunnuntaisin is a Finnish adverbial form meaning "on Sundays" or "every Sunday." It expresses habitual or recurring action tied to the day Sunday and is used to indicate that something regularly happens on that day of the week.

Etymology and formation: the word derives from sunnuntai (Sunday) with the distributive adverbial suffix -sin, a common pattern in Finnish for forming expressions of recurring time (compare maanantaisin, tiistaisin). The suffix marks repetition or habitual occurrence rather than a single instance.

Grammar and usage: sunnuntaisin functions as a temporal adverb and typically appears with verbs to describe routine activities, for example "Sunnuntaisin käyn kirkossa" ("On Sundays I go to church"). It can be used with frequency adverbs for emphasis or negation and is compatible with various verb tenses to indicate habitual past or present actions. Context determines whether it implies every Sunday, most Sundays, or regularly on Sundays.

Pronunciation: typical Finnish pronunciation can be approximated as [ˈsunːuntɑisin], with geminated consonants characteristic of Finnish phonology.

Related forms: other weekdays form similar adverbs (e.g., maanantaisin, tiistaisin), and temporal expressions in Finnish also use alternative constructions such as "sunnuntaina" to refer to a specific Sunday rather than a recurring event.