The kopi system
Kopitiam coffee is built on a compact code: the base word plus a modifier for milk and sugar. Kopi is coffee with condensed milk and sugar; kopi-O drops the milk; kopi-C swaps condensed milk for evaporated milk and less sugar; adding "kosong" removes the sugar entirely.
Tea follows the same logic
Teh follows the identical modifier system — teh, teh-O, teh-C, teh-O kosong — just with tea instead of coffee. Add "peng" to any of these for the iced version.
Beyond the basics
Milo (the chocolate malt drink) gets the same treatment too — Milo peng is a genuine local favourite, not just a kids' drink. Once the modifier system clicks, ordering anywhere in Singapore becomes second nature.