The vowels are: a e i o u. There is dispute whether the –ATR vowels are phonetic variants or separate phonemes.
{| class="wikitable" style=text-align:center
! colspan="2" |
!Front
!Central
!Back
|-
!Close
![+ATR]
|
|
|
|-
!Near-close
![-ATR]
|
|
|
|-
!Mid
![+ATR]
|
|
|
|-
!Open-mid
! rowspan="2" |[-ATR]
|
|
|
|-
!Open
|
|
|
|}
There are two underlying tonemes, L (low) and H (high); phonetically, L, H, mid, HL, and LH are all found.
Metathesis is an extremely common and regular grammatical phenomenon in Fur: when a consonant pronoun prefix is prefixed to a verb that begins with a consonant, either the verb's first consonant is deleted or it changes places with the following vowel; e.g.:
There are also various assimilation rules.
Writing
Fur is written in the Latin alphabet with the addition of the letters a̱ (a with macron below), ɨ, ŋ, and ʉ, and the digraph ny.
High tone is marked by the acute accent, falling tone is marked by circumflex, rising tone is marked by caron ("wedge"), and low tone is unmarked.