začaly

In a sentence

• Začaly se tady objevovat nové obchody.

  New stores started to appear here.

  Here, 'začaly' is used to describe the initiation of an activity, in this case, the appearance of new stores.

• Děti začaly tancovat, jakmile začala hudba hrát.

  The children began to dance as soon as the music started playing.

  In this sentence, 'začaly' conveys the commencement of an action carried out by a plural subject, the children.

• Hvězdy začaly pomalu mizet z oblohy.

  The stars slowly began to vanish from the sky.

  Here, 'začaly' refers to the onset of an observational phenomenon, the disappearance of stars.