He has some questionable moments, but I think there’s also an element of bilingualism here. His mother is Belgian I believe, but Lando doesn’t speak Dutch or French, so he probably didn’t grow up bilingual. That means his mother spoke to him in English (which is, I assume, her second language). Her English probably isn’t perfect, as it is a second language, and children are likely to mirror the language/accent of their parents. However, that shouldn’t really effect his knowledge of “more difficult” words (like punctuality/pronunciation) because those are words you’re likely to learn at school, not at home.