①构成进行时。e.g. We are studying English.
②当副词作状语。e.g. The children came, singing and dancing.
e.g. Falling leaves danced in the air.
I saw many birds flying along the river.
The story is very moving.
①构成完成时。 e.g. The play had begun when we arrived there.
②构成被动语态。e.g. English is widely spoken in the world.
③当副词作状语。e.g. Seen here, the city looks more beautiful.
e.g. a boy named Tom
I saw the girl killed with my own eyes.
I’m interested in English.