We counted to 15 in Greek, let's keep going!
16 δεκαέξι (dekaéxi) - sounds like day-kah-AY-k-see
17 δεκαεπτά (dekaeptá) - sounds like day-kah-ay-p-TAH
18 δεκαοχτώ (dekaochtó) - sounds like day-kah-oh-k-TOH
19 δεκαεννέα (dekaennéa) - sounds like day-kah-ay-n-EE-ah
20 είκοσι (eíkosi) - sounds like ay-EE-koh-see
(from: wikipedia - center for the greek language)
ASL: sixteen, seventeen, eighteen, nineteen, twenty
Italian: sedici, diciassette, diciotto, diciannove, venti
German: sechzehn, siebzehn, achtzehn, neunzehn, zwanzig
Spanish: dieciséis, diecisiete, dieciocho, diecinueve, veinte
French: seize, dix-sept, dix-huit, dix-neuf, vingt