Dutch is my native language and I have experience of teaching my language to adults. I am a tained Dutch lawyer and have been working as a professional translater many years now.
My own children grow up outside the Netherlands and I only speak Dutch with them, which means that I give them nearly continuously conversation trainings in a playful and light harted way ;-)
Other languages that I speak are English, German, French, Swedish (near native), Norwegian, Danish and Spanish (the latter on a B2-level).