X long, X tall, X heavy: dài / cao / nặng + number + unit

To give a size or a weight, put the adjective straight after the thing, then the number and the unit: Cái bàn này dài hai mét. This table is two metres long. English puts the adjective last ("two metres long"); Vietnamese puts it first, and there's no word for "is".

The common ones are dài (long), cao (tall, high), nặng (heavy), rộng (wide, or big for a room) and sâu (deep). For your height, say the metres and then the centimetres: Em cao một mét sáu lăm, I'm 1.65 m. For weight, Saigon says ký: nặng năm mươi ký, fifty kilos. In Hà Nội people also say cân: năm mươi cân.

To ask, put bao nhiêu (how much) where the number would go: Cái này dài bao nhiêu? How long is it? Em cao bao nhiêu? How tall are you?

Temperatures usually need no adjective at all: Hôm nay ba mươi sáu độ. It's 36 degrees today. Nóng or lạnh comes in only to stress an extreme: nóng tới ba mươi tám độ, as hot as 38 degrees.