Mutation of Vowels in Late PG

Table 2

Change illustrated	Examples
	Germanic
Non-Germanic	Old	Modern
PIE G i e e u u o	L ventus, R ветер	Gt winds, O Icel vindr, OE wind	Sw vind, NE wind
L edit, R ест L edere, R есть	OHG izit, OE itep, O Icel eta, OE etan	G ißt, NE eats, G essen, NE eat
Lith sunus, R сын	О Icel sunr, OE	Sw son, NE son
sunu
Celt hurnan	О Icel, OE horn	NE horn, Sw horn

After the changes, in Late PG, the vowel system contained the following sounds:

SHORT VOWELS i e a o u

LONG VOWELS i: e: a: o: u:¹

¹ IE [a:] became [o:]; the new [a:] developed from short [a] before nasals and also from the open [є:] in West and North Germanic.

It is believed that in addition to these monophthongs PG had a set of diphthongs made up of more open nuclei and closer glides: [ei], [ai], [eu], [au] and also [iu]; nowadays, however, many scholars inter­pret them as sequences of two independent monophthongs.