Tifal has a rich aspectual system. Verbs may be separated into four groups based on how they transform from continuative to punctiliar aspect. Some only have vowel and/or simple stem changes, some have suppletive stems, some change compound-final stems, and some which have allomorphs which add -(a)laa-min (or rarely -daa-laa-min) to the stem.Boush 1975, pp. 10-12.
