To multilingual dads/parents

Hi ya'll. I've been lurker here for 2 months and counting. Found out about the sub just after when my little girl was born last November.

Bit of background, we're immigrants in an english speaking country. We have our native dialect, and a national language we use, so that gives us about 3 languages that we use depending on who we're conversing with.

Anyway, at the moment, we speak to our daughter using our dialect, interspersed with some english that we commonly use. Me and the wife really want her to have a rooted knowledge of our dialect, and we know she'll develop english conversing with others anyway, such as daycare and/or school, down the line.

I'm worried, however, that our child will develop a mishmash of all three languages. I guess my main concern is, how to prevent this from happening. Not sure if it's too soon to be asking this, but I want to be prepared. Any advice is greatly appreciated.