Proto-Indo-European is traditionally reconstructed to have used the following phonemes. See the article on Indo-European sound laws for a summary of how these phonemes reflected in the various Indo-European languages.
Consonants[]
| Labial | Coronal | Dorsal | Laryngeal | ||||
|---|---|---|---|---|---|---|---|
| palatal | plain | labial | |||||
| Nasals | *m | *n | |||||
| Stops | voiceless | *p | *t | *ḱ | *k | *kʷ | |
| voiced | (*b) | *d | *ǵ | *g | *gʷ | ||
| aspirated | *bʰ | *dʰ | *ǵʰ | *gʰ | *gʷʰ | ||
| Fricatives | *s | *h₁, *h₂, *h₃ | |||||
| Liquids | *r, *l | ||||||
| Semivowels | *y | *w | |||||
Vowels[]
| length | front | back | |
|---|---|---|---|
| Close-mid | short | *e | *o |
| long | *eː | *oː |