они стали

they started; they became

→ они
phrase Uncommon #16,668
they started; they became With an infinitive, it means “they started”; before a noun or adjective, it means “they became.”
RU: Они стали часто встречаться.
EN: They started seeing each other often.

Вскоре они стали неразлучны.

Soon they became inseparable.

Они стали развязывать шнурки.

They began to untie their shoelaces.

Невестка заговорила её сына, и они стали жить вместе.

The daughter-in-law cast a spell on her son, and they started living together.

— Магазинные воришки (2018)

Они стали снимать.

They started filming.