The Pattern
上手 (skilled) and 下手 (unskilled) are な-adjectives, so the thing you are good at takes が, exactly like 好き.
With a noun:
Person は + Noun が + 上手／下手 + です
- 彼はテニスが上手です。(He's good at tennis.)
With a verb — nominalise it with の first:
Person は + Verb [plain] + のが + 上手／下手 + です
- 友達は料理を作るのが上手です。(My friend is good at cooking.)
Never Say 上手 About Yourself
This is the cultural rule that matters more than the grammar. 私は日本語が上手です sounds boastful, and Japanese speakers avoid it.
Say instead:
- まだまだです。(I've still got a long way to go.) — the standard modest reply
- 少し話せます。(I can speak a little.)
When someone praises your Japanese with 上手ですね, the expected answer is not "thank you" but いいえ、まだまだです。
下手 vs 苦手
Both are negative, but they differ:
| Word | Meaning |
|---|---|
| 下手 | genuinely lacking skill |
| 苦手 | not good at it / don't enjoy it |
苦手 is softer and much more common about yourself, because it admits dislike rather than incompetence. 私は料理が苦手です is safe; 下手です is blunter.
Before a Noun, Add な
- 料理が上手な人 (a person who cooks well)
Adverb Form
Add に to describe how something is done:
- 上手に描けましたね。(You drew that well.)