This is the 4039th most frequent Catalan word.
decoren
"Decoren" means "they decorate" in English.
The verb 'decoren' is used here as a third-person plural form of the present indicative tense of the verb 'decorar', meaning 'to decorate'.
Ells decoren la casa amb flors de primavera.
They decorate the house with spring flowers.
In this sentence, 'decoren' conveys an action regularly performed by the subject in the present tense.
Quan decoren les parets, sempre utilitzen quadres moderns.
When they decorate the walls, they always use modern paintings.
Here, 'decoren' describes the habitual action done by artists as explained by the teacher in present tense.