な-Adj+に
na-adjective adverbial
An na-adjective plus に turns the adjective into an adverb. Instead of describing a thing, it describes how an action is done. 静かだ (is quiet) becomes 静かに (quietly), and きれいだ (is clean) becomes きれいに (cleanly, neatly).
In English this usually matches the “-ly” ending: “quietly”, “skillfully”, “pessimistically”.
1. Describing how an action is done
Put the na-adjective + に right before the verb it modifies.
図書館では静かに話してください。
“Please speak quietly in the library.”
- 図書館（としょかん）= library
- で = at (place of action)
- は = topic marker
- 静かに（しずかに）= quietly
- 話してください（はなしてください）= please speak
2. ～になる: “become ...”
The same に shape appears before なる (to become) to describe a change of state: 元気になる = “get well”, “become healthy”.
妹は元気になりました。
“My little sister got better.”
- 妹（いもうと）= younger sister
- は = topic marker
- 元気に（げんきに）= healthy, well
- なりました = became
な-adjectives take に, い-adjectives take く
i-adjectives form their adverb differently: drop the final い and add く, as in 早い → 早く起きる (get up early).
How to form it
na-adjective + に
- 静か（しずか）= quiet → 静かに（しずかに）= quietly
- きれい = clean, pretty → きれいに = cleanly, neatly
- 上手（じょうず）= skillful → 上手に（じょうずに）= skillfully
Key idea
に aims the quality at the verb instead of at a noun. If you would add “-ly” in English, an na-adjective takes に. Before なる it marks the state something turns into.
Other N5 grammar
Updated .