ー vs small kana vs long kana for writing long vowels


I had thought that for writing long vowels in Japanese, that small kana was
mostly used with hiragana and ー was mostly used with katakana.

I was actually thinking of asking whether there were exceptions but then when
I looked up a word I'm interested in lately I found all these spellings in
WWWJDIC:

  * すげー
  * すげぇ
  * すっげえ
  * すっげー
  * すげえ
  * すっげぇ

Not only are there variants with `ー` and `ぇ`, but also `え`!

In general, how do I know when to use which?

Also do I need to know which is needed to type them? Assume I know how to type
them if I know the spelling, but consider also the case where I've heard a new
word in speech and don't know the spelling yet. (Please don't tell me that's a
software issue with nothing to do with Japanese.)




They are all variations of the same word. The only difference here is the
degree of emphasis and where the emphasis is. For example, "っ" in "すっ" just
represents a bit of pause between "す" and "げ".

"ぇ", "え", and "ー" all represent dragging of the "げ" sound, but "ー" is longer
than "え", and "ぇ" is a very short addition. None is more correct than others,
and the difference is really only significant when you want to precisely
convey the way the speaker has pronounced it.

As a variation, you also see these letters repeated to convey the duration,
such as "すげええええええええ！" or "すげーーーーーーー！" In addition, because the size of the
letter of "ぇ" is smaller than "え", it is also sometimes used not to represent
the volume of the sound as in "すげえええぇぇぇ..." vs "すげええええええ"

Your observation is right that "ー" is normally used with Katakana and not with
Hiragana, and in formal writing you almost never see "ー" with Hiragana. But
the interesting thing about languages is that in some circumstances that
becomes the very reason one intentionally chooses to use "ー" with Hiragana,
like "すげー" to adds a subtle hint that the speaker is not very intelligent.

I'm skipping the last part of your question about how to type it in, since
there's enough answers on that in the comment section.

