1. There was an early three-way split of labiovelars, similar to the later change in Pre-Greek.
2. There was an early simplification of initial clusters containing reconstructed initial laryngeals.
Some pairs suggested to be cognate as a result that stand out to me include:
- *h₁egʷʰ- {to drink} and *píbh₃- {to drink} < **ph₁egʷh₃-
- *h₁eḱw/u- {horse} and *peḱu- {cattle} < **ph₁eḱu-
- *h₂enh₁- {to breathe} and *pnew- {to breathe} < **ph₂(e)nh₁-
- *ḱwóns = *ḱwṓ {dog} and *wĺ̥kʷos {wolf} < **ḱh₃we-l/n-
- *h₂ṓws~h₂éws- {ear} and *ḱlew(s)- {to hear} < **ḱlh₂éw-
- *h₃nṓgʷʰs {nail} and *ǵónu {knee} < **ǵh₃énu, ǵh₃n-o/e-gʷH-
- *h₃nṓmn~h₃némn-~h₃nmén- {name} and *ǵen- {know} < **ǵh₃n-, ǵh₃n-o/e-mn
- *h₂rmos {arm} and *bʰer- {to bear,carry} < **bh₂r-, bh₂r-mos
- *h₂erǵ- {white,bright} and *bʰerHǵós {birch}, *bʰerHǵ- {bright,shine} < **bh₂erǵ-
- *h₂egʷʰ- {snake,creature} and *dʰéǵʰōm {earth} < **dh₂éǵHu-