[maintenance]

I always equated the ー with "おう" for example, where the う indicates to lengthen the お sound. Elongation means to lengthen the pronunciation of the preceding sound, like they said.

If you need help understanding elongation, it's the difference between okasan and okaasan. I'm only demonstrating a comparison with just sound, it isn't really marked the same.

I could be way off, I don't remember!