Syllables ending with H or glottal stop ˀ often sound quite different, depending on whether they are odd- or even-numbered. The result is that many related words have two different spellings.
With sound-based spelling, many related words will have two fairly different spellings, as in
a-s-ahj-wáeˀ ‘you did wash your hands’, versus
s-ahj-óhae ‘wash your hands!’
With meaning-based spelling - which mainly makes use of vowel underlining - the spelling of related words is not so radically different:
a-s-ahj-o̲háeˀ ‘you did wash your hands’, versus
s-ahj-óhae ‘wash your hands!’