Is 遥か a special kind of adjective?


According to the dictionary, it's supposed to be a na-adjective, but it seems
to be used somewhat commonly without the な particle, e.g.

  * 遥か彼方
  * 遥か氷原の彼方
  * 遥か群衆を離れて

I think I've seen a few more variations but can't recall them at the moment.
What's going on here? Is it an exception or there is some rule I'm not aware
of?




Two monolingual dictionaries available online say 遥か can be used adverbially
as well as adjectivally.

  * [デジタル大辞泉](http://dictionary.goo.ne.jp/jn/180287/meaning/m0u/%E9%81%A5%E3%81%8B/)
  * [大辞林](http://www.weblio.jp/content/%E9%81%A5%E3%81%8B)

Similar words include 結構, 色々, 十分, 大変, かなり, 相当, and 特別. As you can see, most of
these are intensifiers.

>   * 大変な事件。 (na-adj.) ／ 大変おいしい。 (adv.)
>   * 特別なプレゼント。 (na-adj.) ／ 今日は特別寒い。 (adv.)
>

I think similar things happen commonly also in English ("fast", "long",
"enough", etc. can work adverbially without "-ly").

**EDIT** : 彼方 itself works both as a na-adjective and a noun, so it can be
modified both by an adverb and a normal adjecitive. 遥か彼方, 遙かな彼方, 遠い彼方, 遠く彼方,
とても彼方 are all valid. The same thing can be said for 昔, which can be modified
both by an adverb and an adjective (遥か昔, 遙かな昔, かなり昔, かなりな昔, 遠い昔, とても昔, ...)




Two monolingual dictionaries available online say 遥か can be used adverbially
as well as adjectivally.

  * [デジタル大辞泉](http://dictionary.goo.ne.jp/jn/180287/meaning/m0u/%E9%81%A5%E3%81%8B/)
  * [大辞林](http://www.weblio.jp/content/%E9%81%A5%E3%81%8B)

Similar words include 結構, 色々, 十分, 大変, かなり, 相当, and 特別. As you can see, most of
these are intensifiers.

>   * 大変な事件。 (na-adj.) ／ 大変おいしい。 (adv.)
>   * 特別なプレゼント。 (na-adj.) ／ 今日は特別寒い。 (adv.)
>

I think similar things happen commonly also in English ("fast", "long",
"enough", etc. can work adverbially without "-ly").

**EDIT** : 彼方 itself works both as a na-adjective and a noun, so it can be
modified both by an adverb and a normal adjecitive. 遥か彼方, 遙かな彼方, 遠い彼方, 遠く彼方,
とても彼方 are all valid. The same thing can be said for 昔, which can be modified
both by an adverb and an adjective (遥か昔, 遙かな昔, かなり昔, かなりな昔, 遠い昔, とても昔, ...)

