system
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human
ELI5 Why most languages use special names for the numbers 11 to 19?

For example, some languages follow  the same rule regardless if its in 10s or 20s:  


Japanese | Chinese |   
Juu-ni       | Shi er      | twelve  
Ni-juu-ni  | Er shi er | twenty two  


But other languages such as:   


English | French | Romanian | Icelandic | German | Philipino |   


Twelve | douze | doisprezece (two towards ten wtf) | tólf | zwölf | labindalawa   
Twenty two | vingt-deux | Douăzeci și doi (two tens and two) | tuttugu og tveir | zweiundzwanzig (two and twenty) | dalawampu't dalawa  


Initially I thought it was an european thing but not even koreans do it like japanese or chinese people, so why is that?
gpt
This is a holdover from older languages.

In English only 10, 11 and 12 have special names 13-19 all have the suffix teen or ten. We say thirteen three-ten, fourteen four-ten, etc

While French has special names for 10-16 but those names are derivative forms of 1-6. (onze douze treize sounds like un deuz trois) but when you get to 17 it's pronounced dix-sept ten-seven

This is common in Germanic languages and languages that have basis in Germanic languages like English.

Likely this comes from a time before writing language and numbers was common place and people were typically mathematically illiterate. The lower numbers 1-12 were frequently used in every day life so they gained special names.

The counting system that includes special words for 11 and 12 is found in Old English which dates from 5th century to 11th century. At this time the learned class spoke Church Latin and counted in Roman Numerals which didn't have unique symbols for 11 and 12 (X, XI, XII, XIII, XIV) or words ūndecim (one ten) duodēcim (two ten)

Some argue that having special names for up to 12 is a result of base 12 numbering, possibly because of the wide spread use of 12 hour time keeping or clocks which dates back as far as the Egyptians. But clocks didn't become common place in Europe until the 14th century, and Arabic numerals about the 12th century.