Learn Icelandic: Potturinn er tómur eftir að við borðum súpuna.

When 'after' introduces a full clause with its own subject and verb (like við borðum), Icelandic requires the two-word conjunction eftir að. If you were just saying 'after the soup' without a verb, you would only use the preposition eftir.

Why is the adjective tómur used instead of just tóm?

In Icelandic, adjectives must match the gender, number, and case of the noun they describe. Potturinn (the pot) is a masculine, singular subject, so the adjective takes the masculine nominative form tómur. If we were describing a feminine noun, it would be tóm.

Both potturinn and súpuna include the word 'the' at the end. Why do their endings look so different?

Icelandic attaches 'the' to the end of the noun, but the exact ending depends on the noun's gender and its grammatical role. Potturinn gets the masculine subject (nominative) ending -inn. Súpuna gets the feminine object (accusative) ending -na because it is the thing receiving the action of being eaten.

Why is the verb borðum in the present tense here?

Icelandic frequently uses the present tense to talk about the future. Depending on the context, this sentence could mean a general habit ('The pot is always empty after we eat the soup') or a future event ('The pot will be empty after we eat the soup').