We have raised our son, 3.5, bilingually since birth. DH speaks only German to him, we speak English or German together, and I speak mostly English to him with some German. Preschool is English.
He could clearly understand everything in both languages from a young age. He started speaking in full sentences in English towards the age of 3. So far he doesn't speak German, maybe the odd word.
His older sister wasn't raised bilingually, just a little German on holiday as I didn't meet my DH til she was 5, so she speaks English with him.
I understand productive skills can come later than receptive skills. And I have a PhD in bilingualism, but it's different raising your own kids!
What are others' experiences in real life? Dh starting to wonder if he'll ever speak German/should he insist (I think not to!).