Do all な-adjectives come from Chinese?


In [this](https://www.youtube.com/watch?v=Vrf9EkKfCb8) video it is said that
"な-adjectives come from Chinese and tend to be written in all kanji or
sometimes in hiragana because the original kanji is too complicated." But
い-adjectives are written in kanji too, aren't they? (e.g. 楽しい）So, in terms of
writing, is there really a principal difference?

Is it true that all な-adjectives come from Chinese? It's rather surprising
because some な-adjectives express such common concepts (e.g.元気、賑やか、静か、etc.)...




The answer is no. Some na-adjectives are from Western languages (e.g., スマートな,
アバンギャルドな) and some are from native Japanese words (e.g., 朗らかな, 静かな). As an
aside, there are also a few i-adjectives coined from English (e.g., エモい, エロい,
ラグい), although they are mostly slang.

As for spelling, it is true that the dictionary forms of most na-adjectives
are written in **all** -kanji (e.g., 簡単, 健康), whereas the dictionary form of
i-adjectives contain at least い.




The answer is no. Some na-adjectives are from Western languages (e.g., スマートな,
アバンギャルドな) and some are from native Japanese words (e.g., 朗らかな, 静かな). As an
aside, there are also a few i-adjectives coined from English (e.g., エモい, エロい,
ラグい), although they are mostly slang.

As for spelling, it is true that the dictionary forms of most na-adjectives
are written in **all** -kanji (e.g., 簡単, 健康), whereas the dictionary form of
i-adjectives contain at least い.

