Song: A repetitive, almost dreamy phrase with characteristic whistles and twitters - ending in a drawn-out, nasal "tjeeeeb" or "dreey" that can go on for several seconds. It readily sings from exposed spots such as treetops and aerials.
Call: A distinct "chup-chup" or a rapid "jit-jit" - heard year-round in flocks.
Alarm: A sharp, repeated "tett-tett" when disturbed at the nest.
Listen to European Greenfinch calls on xeno-canto and see reported observations on Artportalen (the Swedish species observation system).