What is the difference between 特殊 and 特別?

Question

I've got two questions. Firstly, what is the difference between 特殊 tokushu and 特別 tokubetsu?

Secondly, is it true that all these grammar forms are correct:

• 特別な tokubetsu na ＋ [noun]
• 特殊な tokushu na ＋ [noun]
• 特別の tokubetsu no ＋ [noun]
• 特殊の tokushu no ＋[noun]

Answer 1

I'm a Japanese student studying English at university. Let me try and answer your question.

We use 特殊 tokushu in academic situations, describing something strange or crazy.

In contrast, we say 特別 tokubetsu in casual situation, describing something precious or valuable.

For example, we say 「君は特別な人だ」(kimi wa tokubetsu na hito da - "You are precious to me"), but we don't say 「君は特殊な人だ」(kimi wa tokushu na hito da) in that sense.

When we say 「君は特殊な人だ」, this means "You are strange" or "You are not an ordinary person."

The answer for your next question is clear:

「特別な」and「特殊な」are correct, and they are not noun but adjective that can be translated as "special" or "peculiar."

「特別」are「特殊」nouns. We don't say 「特別の」or 「特殊の」in Japanese. What's more, to be precise, "special" is an adjective (形容詞 keiyōshi) in English, but 「特別な」「特殊な」is 「形容動詞」(keiyōdōshi) in Japanese.

「「形容動詞」can be classified as adjective, but we distinguish 「形容詞」

Answer 2

Another way to look at it could be the difference between "special" and "specialized". Both words do technically refer to something "not normal", but 特殊 is more often used for something specialized, something that is particular to a case. 特別 is usually used to mean "special" as in "outside the norm" - it can be used for good things or for bad, but usually it's used for good things(I believe). 特別 can be used in sort of the same way as 特殊, as well.

Look at these sentences(from alc):

特殊なペンでイラストや文字を入力することもできます。 (Using a specialized pen, users can input pictures and characters.)

特殊なハードウェアを作る (to create specialized hardware)

These indicate that the noun being modified is something otherwise normal that has been tailored to a specific case.

特別, however, can generally be used for both:

特別な扱いはしないでほしい。 (I'd like it if you didn't give me special treatment.)

特別な企画に取り組む (to work on a special project)

Both give sentences give a sense of something "special", or something "outside the norm".

From personal experience, I see 特殊 being used more for concrete objects, such as 特殊な道具 or 特殊部隊.