な-Adjective に + Verb
N5Ngữ phápTurn a な-adjective into an adverb by adding に.
Usage
な-Adjective (remove な) + に + VerbExplanation
To make a な-adjective modify a verb, remove the な and add に. This form describes how an action is performed. For instance, 静か（な） → 静かに, 親切（な） → 親切に.
Example sentences (4)
彼は静かに話す。Kare wa shizuka ni hanasu.He speaks quietly.
部屋をきれいに掃除した。Heya o kirei ni souji shita.I cleaned the room neatly.
彼女は元気に働いています。Kanojo wa genki ni hataraite imasu.She works energetically.
先生は親切に説明してくれる。Sensei wa shinsetsu ni setsumei shite kureru.The teacher explains kindly.