/ë/ is inserted as a transition sound (1) between /k/ and /m/, (2) between /h/ and /m/ of the MP suffix, and (3) between /m/ and /n/.
The second of these insertions is rounded to /ù/ before /m/.
First person plural /-nan/ is realized as /-na/ in final position.
Note: the negative takes the form /-u/ after a consonant.