My two children and I were discussing recently how it is, even though German is their dominant language, they do not feel as if they possess an extensive or differentiated German vocabulary.
Their father is originally from Italy and learnt to speak German as a 10-year-old. He does not speak anymore the Sicilian dialect of his childhood. He studied to be a translator and linguist and so acquired a further four languages along the way.
The way we communicated when our children were living at home was; I spoke English, which my husband and children understand, and they spoke German the whole time, which I’m fluent in. So, I naturally assumed their German would be comparable to all their German schoolmates. Apparently not.
My daughter says she feels as if there was still something missing, some depth to the language, they never learnt. She proposes it has to do with the fact that none of her grandparents were German. Maybe family history and shared family memories are an intrinsic part of the passing on of language. What a lovely notion.