Verbal Morphology

The personal desinences of Inggirian are as follows:

Mood	1s	2s	3s	1p	2p	3p
Irrealis	-Iw	-Is	-In	-IsgAw	-IsAw	-IsIn
Realis	-Aw	-As	-An	-AsgAw	-AsAn	-AsdAn
Conditional	-xAw	-xAsI	-xAnI	-xIsgAw	-xIsAw	-xIsIn

Meanwhile, those of Old Inggirian are as follows:

Positive

	Singular	Plural
1st	-(e)wa	-(e)gawa
2nd	-(e)jig	-(e)gajag
3rd	-(e)g̃	-(e)seg̃

Negative

	Singular	Plural
1st	-(g̃)awi	-(g̃)agawi
2nd	-(g̃)aji	-(g̃)ajawi
3rd	-(g̃)a	-(g̃)ajida

How did the new endings come about?

Possibly the endings exhibited irregular umlaut:

-ewa -ejig -eñ -egawa -egajag -eseñ > -eawa -eijig -eñ -eagawa -eagajag -eseñ > MI -āw -eisg -(i)n -āgāw -āgajg -isin
-ñawi -ñaji -ña -ñagawi -ñajawi -ñajida > -ñaiwi -ñaiji -(ñ)a(ñ) -ñagaiwi -ñajaiwi -ñaijida > MI -ēw -ēs -a(n) -(n)gēw -(n)jēw -ēsda

At this point, some regularization occurs:
Early Middle Inggirian
Positive -āw -eisg -(i)n -āgāw -āgasg -isin, Negative -ēw -ēs -an -ēgēw -ēsēw -ēsdan

Whence Middle Inggirian proper:

Positive -āw -asg -ān -agāw -āgasg -asdan, Negative -ēw -ēs -ēn -egēw -esēw -esdan

Where the jig is up. Late Middle Inggirian:

-Aw -As -An -AsgAw -AgAs ~ -AsgAn -AsdAn; -IAw -IAs -IAn -IsgIAw -IsIAw -IsdAn

By modern times, the falling diphthongs reduce to pure I and we get the modern system.