Linguistic experiments

I have always been interested in linguistics. I am just a standard immigrant, who now thinks and dreams (most of the time) in a foreign language. Moving to Australia gave me many opportunities to observe and discuss what happens to immigrants, then their children and their children. It is fascinating. Let's have a look at Little Miss S. Born overseas, both parents speak Spanish to kids and each other all the time. Until she went to kindergarten, she only spoke Spanish. Give her a couple of months of two days a week in English-speaking environment and a Spanish word doesn't cross her lips. Now what chances have I got to make Hanna speak Polish, when she only hears it from me and usually in shouting commands?

PS
I can see all faults of this portrait, but is was a quick shot while talking, drinking, waiting for a seafood risotto and having a good time.

PS2
One day, when this one particular family from Switzerland comes to visit us, I will write about the biggest possible linguistic experiment on children. One day...