Learn Swedish: Bergakungen gömde guldet i berget. - The mountain king hid the gold in the mountain.

This is a compound word made of berg (mountain) and kungen (the king). The -a- is a linking vowel (fogevokal). While berg usually takes an -s- in modern compounds (like bergsbestigare, mountain climber), older or mythological words often use -a-. This -a- actually survives from an old plural possessive form, so it historically means "king of the mountains".

We see berg used as a compound in Bergakungen, but then as berget at the end. Why?

When a noun is the first part of a compound (like berg- in Bergakungen), it cannot be in the definite form. It drops the definite ending (-et or -en) and uses its stem, sometimes adding a linking vowel like we see here. At the end of the sentence, berget stands alone as a regular noun in its definite form ("the mountain").

Why is the past tense of gömma spelled gömde with only one "m"?

Gömma (to hide) is a regular Group 2 verb, so its past tense is formed by adding -de to the stem (gömm-). However, Swedish spelling rules dictate that a double consonant is usually reduced to a single consonant when followed by another consonant. Therefore, gömmde drops an "m" to become gömde.

Does gömde work the same way if the king was hiding himself instead of the gold?