健はなかなかのスポーツマンだ。

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

very; considerably; easily; readily; fairly; quite; highly; rather; by no means (with negative verb); not readily; middle; half-way point; excellent; wonderful; very good

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

sportsman

be; is; indicates past or completed action; indicates light imperative