Learn Hardcore Norwegian: Jeg trykker på knappen, og komfyren slår seg av automatisk. - I press the button, and the stove turns itself off automatically.

In Norwegian, the verb trykke (to press/push) requires the preposition på when you say “press something.” So you always say å trykke på noe (“to press on something”).

What does slår seg av mean, and why is seg included?

Slå av means “to turn off.” When you add the reflexive pronoun seg, it shows the subject does the action to itself. So slår seg av literally means “[it] turns itself off.”

Can we omit seg and just say komfyren slår av?

No. Without seg, slår av is a transitive verb and needs an object (e.g., slår av lyset – “turns off the light”). To express that the stove automatically shuts itself off, the reflexive seg is mandatory.

Why is komfyren in this form? What does the -en ending do?

Komfyren is the definite singular form of en komfyr (“a stove”). Adding -en makes it “the stove.” Many masculine/feminine nouns form the definite by adding -en.

What part of speech is automatisk, and why doesn’t it change?

Automatisk is an adjective that also works as an adverb without any extra ending. In this sentence it tells you how the stove turns off—i.e. it does so automatically.

Why is automatisk placed at the end of the clause?

In Norwegian, adverbs often follow the entire verb phrase, especially with separable verbs like slår seg av. Keeping slår seg av together and then adding automatisk at the end is the natural word order.

What tense are trykker and slår?

Both are in the present tense: jeg trykker (“I press”) and komfyren slår (“the stove turns”).

Why is there a comma before og, and is it required?

A comma before og connecting two independent clauses is optional in Norwegian. It’s often used for clarity but can be dropped if the clauses are short:
Jeg trykker på knappen og komfyren slår seg av automatisk.