Dear Visitor,
even beginners has the probleme to diffrent the gender of this species.
Here are some small details that only the more expert and specialized
eye succeeds to pick:

flügel beim Hahn

shoulder (small copritrici andirons) black polishes of the male



Il Cardellino
Maske beim Hahn
maske bei der Henne
zum Seitenanfang
Stieglitze
feature of the gender

This photos are taken from
© Massimo Natale / Il Cardollino with his kindly agreement.

Goldfinch / Hen (Carduelis carduelis)
Flügel Henne
shoulder gray-green in the female (tonotice the black one of the wings more opaque regarding the male of the previous figure)
in the male the template abundantly exceeds the posterior edge of the eye (see arrow)
the template in the female in kind does not exceed the half of the eye; the head is introduced more rounded off than that one of the male (see arrow)
Photos © Massimo Natale
Goldfinch / Cock (Carduelis carduelis)