It’s pretty common knowledge that 1-5 & 10 are used at a higher frequency than 6-9, as are numbers below 50 than above. We like lumping them together in convenient sets too : a pair, a couple, a dozen… English five & fist, German fünf & Faust and Polish pięć & pięść are all derived from Proto Indo-European *penkwe-.
Currently looking at Croatian which has oddities of its own. If we look at telling the time, it has :
| It’s 1 o’clock | Jedan je sat | Lit. One is hour |
| It’s 2 o’clock | Dva su sata | Lit. Two are of hour |
| It’s 3 o’clock | Tri su sata | Lit. Three are of hour |
| It’s 4 o’clock | Četiri su sata | Lit. Four are of hour |
| It’s 5/6/7, etc. o’clock | Pet/Šest/Sedam je sati | Lit. 5/6/7 is hours |
Where :
- sat = hour (nominative singular)
- sati = hours (nom. plural)
- sata = hour (genitive singular, or plural, not sure which)
I'm curious, are there any other languages out there that treat 2 to 4 like this?