"magic" can be a noun or adjective. "magical" is always an adjective.

"magic"可以是名詞名詞或形容詞。“magical”總是一個形容詞。

Harry Potter studies magic at his school. (noun)

哈利波特在他得學校學習魔法。(名詞)

Harry Potter has a magic wand (adjective).

哈利波特有一根魔杖(形容詞)。

Harry Potter has magical adventures. (Adjective)

哈利波特有神奇得冒險經歷。(形容詞)

Harry Potter has to say a magical incantation while using his wand. (Adjective)

哈利波特在使用他得魔杖時必須念一個魔法咒語。(形容詞)

you use magic to describe something that does things, or appears to do things, by magic. 你可以用magic（有魔力得）來描述某物通過魔法做某事。

Something that is magical seems to use magic or to be able to produce magic

有魔力得（magical）東西似乎使用魔法或能夠產生魔法。

You can say that a place or object is magical when it has a special mysterious quality that makes it seem wonderful and exciting.

你可以說一個地方或物體是神奇得（magical），它有一種特殊得神秘性質，使它看起來美妙和令人興奮。

Grammatically, it would be correct to interchange "magic" and "magical' when you want to use an adjective, BUT in some specific cases, one term is in common usage, while the other is not used. Specifically in English, you always hear "magic wand", not "magical wand".

從語法上講，當你想使用形容詞時，將“magic”和“magical”互換是正確得，但是在某些特定得情況下，一個術語是常用得，而另一個則不用。特別是在英語中，你總是聽到“magic wand”（魔杖），而不是“magical wand”。