Learn Danish: Mødrene og fædrene er ved skolen. - The mothers and the fathers are at the school.

Both of these are irregular family words. En mor (a mother) becomes the plural mødre (mothers). To say "the mothers", you add the definite plural ending -ne to get mødrene. The exact same pattern happens with en far (a father), which becomes fædre and then fædrene.

What is the rule for making plural words definite (meaning "the") in this sentence?

In Danish, you usually add -ne to the plural form of a word to say "the". Since the plural of mother is mødre, adding -ne makes it mødrene (the mothers).

Why does the sentence use ved for "at" instead of i or på?

The word ved translates to "at" or "by" and usually describes a physical location right next to something. Saying they are ved skolen means they are waiting by or right outside the school building, like parents picking up their kids.

Why does skolen have an -n at the end?

In Danish, "the" is attached to the end of the noun. Because en skole (a school) is an en word that already ends in an e, you just add an -n to the end to make it skolen (the school).