N5
な形容詞
なけいようし
Adjectives that are also nouns
大好きな野菜です。
A vegetable that I love.
Explanation
The stem of a な-adjective looks like a noun (「便利」, 「有名」, 「親切」), and as a predicate it takes 「です」 or 「だ」 just like a noun. Before a noun it needs 「な」, which is why it is called a な-adjective: 「静かな町」 (a quiet town).
Mixed up with
Before a noun: an い-adjective connects directly, 「高い山」; a な-adjective needs 「な」, 「静かな山」.
Before a verb: an い-adjective becomes 「く」, 「速く走る」; a な-adjective takes 「に」, 「静かに走る」.
Joining two clauses: い-adjectives use 「〜くて」; な-adjectives use 「で」, 「静かで広い部屋」.