Contact Form plugin- for Spanish

I am using the “Contact form” plugin, and I am trying for it to display in spanish.
Under “additional options” I have aded Spanish, and seems to have activated it for the “Display Text- after email is sent” part. However the form itself is still showing all the required fields in english, and I need them in spanish.
Kindly advise as to how to fix this.
Thank you in advance!