duvati

1. (of wind) to blow
   Napolju duva jak vetar. — A strong wind is blowing outside.
   Košava duva već tri dana. — The košava has been blowing for three days.
2. (of a person) to blow
   Policajac mu je rekao da duva u alkotest. — The police officer told him to blow into the breathalyzer.
   Nemoj da duvaš u mikrofon. — Don't blow into the microphone.
3. (from exertion) to puff; to pant
   Popeo se na peti sprat i duvao kao lokomotiva. — He climbed to the fifth floor, puffing like a steam engine.
4. slang (of drugs) to smoke weed
   On duva travu još od srednje škole. — He's been smoking weed since high school.

'To blow into something' is duvati u + acc. (u balon, u alkotest).