Wow - 5 languages!! I am so envious. My family came to US in the early 1900's. They wanted to be "Americans" so they only spoke Italian when they didn't want the children to understand. My Mom speaks no Sicilian at all (her father came here as a little boy, about 6 years old, and her mother was the first in her family born here). My Dad was the second born in his family (8 years younger then the oldest), so he grew up speaking Italian, but as he got older and more children were born and lived there was less spoken amongst them so by the time #7 came along she speaks very little.
I wanted my Father to teach me, but if it is not part of the home life on a regular basis it's almost impossible.
I know enough Spanish to get myself into trouble lol :)