Subject + 成群 + Verb Phrase
成群 (chéngqún) means "in groups" or "in flocks," describing the behavior of gathering together in large numbers. It is commonly used to describe animals that naturally congregate, such as birds, fish, or other social creatures.
秋天的时候,大雁成群地飞往南方。
Qiūtiān de shíhou, dàyàn chéngqún de fēi wǎng nánfāng.
In autumn, wild geese fly south in flocks.
海里的鱼成群游过,场面非常壮观。
Hǎi lǐ de yú chéngqún yóu guò, chǎngmiàn fēicháng zhuàngguān.
Fish in the sea swam past in schools — it was a spectacular sight.
草原上的羊成群地在山坡上吃草。
Cǎoyuán shàng de yáng chéngqún de zài shānpō shàng chī cǎo.
Sheep on the grassland graze on the hillside in flocks.