I noticed that the numbers 1 - 10 in Irish sound very similar to those in Spanish and French. Did the Celts adopt any of their numbers from the Romans for commercial purposes by any chance?

I believe that they are all native, although individual numbers and even entire number systems do get borrowed from language to language.

The numbers for the Indo-European languages show quite a bit of similarity, especially if you know a little about sound changes. Notice how a hard 'c' sound changes to a 'p' sound or an 'f' (=ph, right?). Sometimes the hard 'c' just gets squashed or exploded (so much for grammarese!) into an English 'ch' (as in 'church') or a German 'ch' (Achtung). Look at Irish and Italian 'four' and compare with Breton and Romanian, and then English, Norwegian and Dutch.

I left out a lot of diacritical marks and sometimes indicated a rough pronunciation in parens. There may be a couple of spelling errors:


Irish /Breton /Dutch

aon /unan /een
dó /daou /twee
trí /tri /drie
ceathair /pewar /vier
cúig /pemp /vijf
sé /c'hwec'h /zes
seacht /seizh /zeven
ocht /eizh /acht
naoi /naou /negen
deich /deg (pr. dek) /tien

Norwegian /Czech /Polish

en /jeden /jeden
to /dva /dwa (dva)
tre /tri /trzy
fire /ctyri (chtihrjih) /cztery
fem /pet (pyet) /piec (pientch)
seks /sest (shest) /szecz (sheshch)
sju /sedm /siedem
åtta /osm (osem) /osiem
ni /devet /dziewiec
ti /deset /dziesiec


Hindi* /Italian /Romanian

eek (ayk) /uno /unu
doo /due /doi
tiin /trei /trei
char /quattro /patru
panch /cinque /cinci (chinch')
chee (chayk) /sei /sase (shase)
sat /sette /sapte (shapte)
at /otto /opt
nau /nove /noua
das /dieci /zece

* This is phonetic, of course. Hindi uses its own script.

From what I've read, the similarities in terms of numerals is purely because all these languages are cognate Indo-European languages. Similarities between numerals being just one of many similarities between nearly all european languages.

Go díreach. Exactly.

Eascraíonn na teangacha Ind-Eorpacha as aon fhoinse amháin agus, i gcás na n-uimhreacha, tharla na difríochtaí eatarthu de réir a chéile le himeacht ama.

Ní mar i gcéanna teangacha eile i gcónaí. Mar shampla, ghlac cainteoirí na Cóiréise, na Seapáinise agus na Téalainnise na huimhreacha ón tSínis. Ba mhór an chumhacht agus an tionchar a bhí ag na Sínigh, agus chomh maith leis sin, bhí córas comhairimh thar a bheith simplí acu.

Tá teangacha ann a bhfuil córais chasta acu -- Níl an Ghaeilge ró-shimplí ina leith sin agus tá teangacha eile níos casta go fóill. I leabhar Zulu áirithe baineann na húdair úsáid as na huimhreacha Béarla. Molann siad an córas bundúchasach a fhoghlaim freisin le meas agus moladh na gcainteoirí dúchais a bhaint amach ach deir siad go bhfuil an córas céanna chomh deacair go mbaineann na Zulu-nna féin úsáid as na huimhreacha Béarla go forleathan.