The root -díín is irregular, since *-dį́ would be expected. -díín is invariable in shape (i.e., there are no other forms for different aspects or tenses), although a distinction between imperfective and perfective could be made. According to Young (1992), bases containing prefix yíní- (“directed at”) have neuter imperfective stems, while the rest have neuter perfective.
|Theme||Category||Bases||Transitive bases (O + ł)|
|di||operative||light shines (on P)||S casts light (on P)
See also Appendix: Roots and stems derivation.