This is the 1874th most frequent Catalan word.
formava
"Formava" means "formed" or "was forming" (third person singular, imperfect tense) in English.
In this sentence, 'formava' refers to the repeated or ongoing action in past where the wind created dunes.
El vent formava dunes a la sorra.
The wind formed dunes in the sand.
The word 'formava' describes a past habitual or ongoing action that he was a member of the group.
Ell formava part del grup de música.
He was part of the music group.
Here, 'formava' conveys that the experience gradually influenced or constructed his character in the past.