This is the 6th most frequent Finnish word.
kun
The Finnish word "kun" means "when," "as," "since," or "because," depending on the context.
Here, 'kun' is used as a conjunction to denote a temporal relationship between actions, specifying 'when' the sun rises.
Kun aurinko nousee, aloitamme päivän.
When the sun rises, we begin the day.
In this sentence, 'kun' functions as a conjunction to express a condition or situation during which the main action occurs, meaning 'when' in the context of a recurring situation.
Hän nauraa, kun hän on iloinen.
He laughs when he is happy.
Here, 'kun' introduces a causal context, suggesting that the preceding action ('working a lot') is linked to the result ('being tired'), meaning 'as' or 'since'.