Learn Finnish: Hän ei ole kotona, koska hän lentää tänään Espanjaan. - He is not at home, because he is flying to Spain today.

In Finnish, to make a verb negative, you use the negative verb (ei for "he/she") followed by a special base form of the main verb. For the verb "to be", that base form is ole. So, hän on (he is) becomes hän ei ole (he is not).

Why is "at home" translated as kotona instead of using the normal "in" ending like kodissa?

While you might expect the "in" ending (-ssa/-ssä) to make kodissa (in the home), the word for "home" uses an older grammar rule to mean "at home". As a beginner, it is easiest to learn kotona as a fixed expression that you will use whenever someone is at home.

The translation says "he is flying", but the Finnish sentence just says hän lentää. Where is the word for "is"?

English has two present tenses: "he flies" and "he is flying". Finnish only has one! The single verb lentää covers both meanings depending on the context. You should never add the verb on (is) when someone is currently doing an action.

Why does Espanja (Spain) become Espanjaan at the end of the sentence?