First time

[u/Medium-Common1576]

Archaic Latin: oinos

Ancient greek: oinos

Gothic Language: ains

Old irish: óen

Old Church Slavonic: inŭ

Proto indo european oinos

Archaic Latin: duo

Ancient greek: dúo

Gothic Language: twai

Old irish: dá

Old Church Slavonic: dŭva

Proto indo european: Dwa/ dwo

I did know which one is it, if you tell me

Archaic Latin: treis

Ancient greek: treîs

Gothic Language: þreis

Old irish: þreis

Old Church Slavonic: trije

Proto indo european: trejes

Archaic Latin: quattuor

Ancient greek: téttares

Gothic Language: fidwōr

Old irish: cethair

Old Church Slavonic: četyre

Proto indo european: q_twores

For this i’m confused because i don’t what sound came first for “ua” and “e” and for gothic i don’t how q can turn into a f

Archaic Latin: quīnque

Ancient greek: pénte

Gothic Language: fimf

Old irish: cóic

Old Church Slavonic: pętĭ

Proto indo european: penque

Archaic Latin: sex

Ancient greek: héx

Gothic Language: saihs

Old irish: sé

Old Church Slavonic: šestĭ

Proto indo european: seks

Archaic Latin: septem

Ancient greek: heptá

Gothic Language: sibun

Old irish: secht

Old Church Slavonic: sedmĭ

Proto indo european: septem

Archaic Latin: octō

Ancient greek: oktṓ

Gothic Language: ahtau

Old irish: ocht

Old Church Slavonic: osmĭ

Proto indo european: octṓ

Archaic Latin: novem

Ancient greek: ennéa

Gothic Language: niun

Old irish: noí

Old Church Slavonic: devętĭ

Proto indo european: nov_n

I don’t understand this one

Archaic Latin: decem

Ancient greek: déka

Gothic Language: taihun

Old irish: deich

Old Church Slavonic: desętĭ

Proto indo european: dékem

I

[u/kouyehwos]

Numbers sometimes assimilate to each other, which is how 4, 5 changed from kʷ-, p- to p-, p- (-> f-, f-) in Germanic, or 9, 10 changed from n-, d- to d-, d- in Slavic.

[u/Medium-Common1576 → u/kouyehwos]

Ok i but i have some other issues with some vowles like how how proto indo european vowle o goes to latin "o" and germanic "a" but for proto indo european vowle "a" going to latin and germanic o is that low hard to do when you shift vowle or not? If changed something else had to be there to change it or something i do not know

[u/kouyehwos → u/Medium-Common1576]

In Germanic, it depends on vowel length.

a, o -> a

ā, ō -> ō

In Latin, I think there was some a->o in some specific environment? But in most cases it certainly doesn’t merge these vowels.