Learn Hardcore Finnish: Minä opiskelen suomea, kuitenkin olen väsynyt.

Kuitenkin functions as a contrastive adverb, equivalent to "however" in English. It connects the two independent clauses by showing a shift—from studying Finnish to feeling tired.

Why is the subject pronoun minä used only in the first clause and omitted in the second?

In Finnish, verb conjugations already indicate the subject. Once minä (meaning "I") is introduced in the first clause, it is unnecessary to repeat it. The verb olen in the second clause clearly implies that the subject remains the same.

Why is suomea in the partitive case rather than the nominative form suomi?

When talking about studying a language, Finnish typically uses the partitive case to express an ongoing or non-finalized action. Here, opiskelen requires a partitive object, so suomi becomes suomea.

Why is there a comma before kuitenkin in the sentence?

The comma is used to separate two independent clauses. It signals a pause that helps clarify the contrast between the action of studying Finnish and the state of being tired.

Could mutta be used instead of kuitenkin, and what is the difference between them?

Yes, mutta (meaning "but") could be used. The main difference is nuance and formality: kuitenkin tends to be slightly more formal and emphasizes an unexpected contrast, while mutta is more common in everyday language with a straightforward contrasting meaning.