Questions & Answers about Är bläcket han använder farligt för huden?
Why is the word som missing between bläcket and han?
This is a classic example of dropping the relative pronoun. Just like in English where you can say "the ink he uses" instead of "the ink that he uses", Swedish allows you to drop som when it represents the object of the relative clause. Because han is the subject doing the using, the object pronoun som is completely optional here.
Would it be wrong to include som and say bläcket som han använder?
Not at all! Including som is always grammatically correct and perfectly natural. However, dropping it is extremely common in both spoken and written Swedish, so it is important to recognize this structure when you encounter it.
Why does farligt end with a -t when it comes right after a verb?
The adjective farligt is describing the noun at the beginning of the sentence: bläcket. Because ett bläck is a neuter word, the adjective takes the neuter -t ending. This agreement applies even when a relative clause like han använder interrupts the sentence and separates the noun from its adjective.
Why do we use the preposition för instead of till here?