Kirundi, like many Bantu languages, is tonal. There is a phonemic distinction between long and short vowel sounds, and tone can be found in the rising or falling of long vowels.

The syllable structure is consonant + vowel (CV).

For more on Kirundi Phonology, https://www.livelingua.com/fsi/FSI%20-%20Kirundi%20Basic%20Course%20-%20Student%20Text.pdf