Without, when ordering: dish + không + ingredient

When you order, put không before something you don't want, straight after the dish or drink: nước cam, không đá (orange juice, no ice), phở bò, không hành (beef phở, no onions). You know không before a verb as "not". Before a food word, it means "no" or "without". At the end of a question it asks yes or no, so the seller may ask Có đá không? (Ice?), and you answer Không đá.

It goes at the end of the order: Cho em một ly nước cam, không đá. One orange juice, no ice, please (in Hà Nội, một cốc). Add nha and the person's word to sound friendly: Một tô phở bò, không hành nha chị.

For less of something, use ít in the same place: ít đường (not too sweet), ít đá (not much ice). For more, say thêm: Cho em thêm đá. More ice, please.

Menus use the same pattern: cà phê đen không đường is black coffee with no sugar. In Saigon you'll also hear không bỏ hành, "don't put onions in".

This is for what goes into your food and drink. "Without doing something" is a later pattern, with mà không.