Learn Portuguese (Portugal): A palhaçada apavorou o miúdo e ele desatou a soluçar. - The clowning terrified the boy and he started sobbing.

The phrase desatar a followed by an infinitive means to suddenly or violently start doing something, most commonly crying, laughing, or talking. While começou a simply means he started, desatou a soluçar paints a vivid picture that the boy burst into sobs abruptly and uncontrollably.

Could we have used pôs-se a soluçar here, since the lesson covers both expressions?

Yes, but there is a subtle difference in nuance. Pôr-se a often implies a slightly more deliberate or sustained initiation of an action, almost like settling into doing something. Desatar a highlights a sudden loss of restraint, which is a much better fit for a child reacting to sheer terror.

How is the word palhaçada formed?

It comes from the noun palhaço (clown) plus the suffix -ada. This suffix often indicates an action typical of the root noun or a collective group of something. Here, palhaçada means clowning around or foolishness. You also see this suffix in words like rapaziada (a group of young people) or facada (a knife strike).

Is apavorou just a synonym for the verb assustou?