Sweet unless you say so

Order a coffee or tea at a Thai stall and it arrives sweet by default: sugar syrup, sweetened condensed milk, often both. That is the normal recipe, not a mistake. To change it, add หวานน้อย 'less sweet' or ไม่หวาน 'not sweet' right after the drink's name: กาแฟเย็น หวานน้อย. On milky drinks ไม่หวาน may still taste sweet, because condensed milk is part of the base; add ไม่ใส่นม if you want none. Many chain cafés let you pick a sweetness level, sometimes printed as percentages on the menu. ชาเย็น, the orange Thai iced tea, is famously sweet even at หวานน้อย; that is part of its charm.