Learn Swedish: Minnet från dagen då vi gifte oss är vackert. - The memory from the day when we got married is beautiful.

In Swedish, då is used as a relative adverb to refer back to a specific time or noun that was just mentioned in the main clause (in this case, dagen). While när also means 'when', it is typically used for questions or general time clauses, like 'When we were young'.

Could I use som instead of då here?

No, you cannot use som here. The word som is a relative pronoun used for 'that' or 'which' when referring to subjects or objects. Because we are talking about a point in time (the day when something happened), you must use the relative adverb då.

Why is the word oss required after gifte?

The verb for 'to get married' is reflexive in Swedish: att gifta sig. Because the subject of the relative clause is vi (we), you have to use the matching reflexive pronoun oss. In Swedish, you literally say 'we married ourselves'.

Why does the adjective vackert end in a -t?

The adjective describes the main subject of the sentence, which is minnet (the memory). Because ett minne is an ett-word, the adjective must take the neuter -t ending to agree with it. This rule applies even when the noun and adjective are separated by a long relative clause.