Learn Swedish: Tröjan tvättas skonsamt i det kalla vattnet. - The sweater is washed gently in the cold water.

The word is built from the root of the verb skona (to spare or treat carefully). Adding the suffix -sam turns it into the adjective skonsam (gentle). In this sentence, it gets an extra -t at the end because it acts as an adverb describing how the sweater is washed.

Why does the verb tvättas end in an -s?

This is the passive voice, which focuses on the action happening to the sweater rather than who is doing the washing. By adding an -s to the present tense verb tvättar (washes), it becomes tvättas (is washed).

Why do we say det kalla vattnet instead of just i kalla vattnet?

Swedish uses the double definite pattern when an adjective describes a specific noun. You need three parts: the independent definite article det (because water is an ett-word), the adjective with an -a ending (kalla), and the definite noun itself (vattnet).

Why is the definite form of vatten spelled vattnet and not vattenet?