Is た形 required when using 自動詞 as an adjective?


From the grammar book I learned that when 自動詞 is being used as an adjective,
it should change its form to the た形, for example:

  * 優れ{すぐれ} **た** 学生
  * 拗れ{こじれ} **た** 話し

But can I say 優れ **る** 学生 or 拗れ **る** 話し? Why?




You can, but the meaning will change.

Basically, you can use 辞書形 (dictionary), た形 (perfective), 可能形 (potential) verb
phrases, and of course all of their negative forms, to modify a noun.

  * 【辞書形】飛ぶ{とぶ}豚{ぶた} _a pig that will fly_
  * 【た形】飛んだ豚 _a pig that flew_
  * 【可能形】飛べる豚 _a pig that can fly_

A lot of other derivatives work too:

  * 【〜いる】飛んで **いる** 豚 _a pig that is flying_
  * 【〜しまう】飛んで **しまう** 豚 _a pig that flies unintentionally_
  * 【〜そうな】飛び **そうな** 豚 _a pig that seems like it's going to fly_ , etc.

So the meaning of your example will change accordingly: こじれ **た** 話 ( _a
matter that became complicated_ ) vs. こじれ **る** 話 ( _a matter that will become
complicated_ ).

* * *

優れる is a verb that needs special attention though. The dictionary form will
want some kind of prepositional object. And when 優れる takes an object, it is
more commonly used in the continuous form.

  * 【た形】優れ **た** 学生 _an excellent student_
  * 【辞書形】優れ **る** 学生 ← unnatural 
    * 【目的語+辞書形】 **スポーツに** 優れ **る** 学生 _a student who excels in sports_ ← OK
    * 【目的語+進行形】 **スポーツに** 優れ **ている** 学生 ← more common

