/ë/ is inserted as a transition sound (1) between /n/ and /m/ and (2) between /w/ and /n/.
Unstressed /ë/ of the inverse suffix is elided.
/w/ of the third person suffix is vocalized as /u/ between consonants (disregarding the inserted /ë/).
Note: this form represents one of three possible treatments of the same underlying form, all representing the same meaning.