Learn Finnish: Hän on pätevä, koska hänellä on tutkinto. - She is qualified, because she has a degree.

The adjective pätevä requires the illative case (the "into" case) when specifying what someone is qualified for. For example, if you wanted to say "She is qualified for the task", you would say Hän on pätevä tehtävään. In this sentence, however, it is used on its own to just mean "qualified" in general.

The word pätevä looks like a verb participle. What verb does it come from?

It comes from the verb päteä, which means "to be valid" or "to hold true". The -vä ending makes it a present active participle, which effectively turns the verb into an adjective. Over time, it evolved to mean "competent" or "qualified" when describing a person.

As a quick refresher, why do we say hänellä on instead of using a verb for "to have"?

Finnish lacks a direct verb for "to have". Instead, you use the adessive case (ending in -lla or -llä) on the person who possesses something, followed by the third-person verb on (is). So hänellä on tutkinto literally translates to "on her is a degree".

Do I always need a comma before koska?

Yes! Unlike English, where the comma before "because" is often optional, Finnish grammar strictly requires a comma before subordinate conjunctions like koska, että, and kun when they separate two full clauses that each have their own verb (in this case, on appears in both halves).