gwizdanie Englisch:

He was whistling a tune.

He walked down the street whistling cheerfully.

The kettle is whistling on the stove.

He sauntered through the park whistling a tune he'd learned in his youth.

The boomerang hurtled whistling through the air.

Imogen of the Internet can connect to dial-up BBSes by whistling into a funnel attached to a phone line.

My sister was whistling merrily.