Learning a new language isn’t an easy task; it takes a lot of effort, but it’s highly rewarding. The best time to learn is when one is young because it’s so much easier to pick up from trial and error or conversations, which is also why many parents encourage their kids to do that.
Unfortunately, in this case, when a pre-schooler picked up a bit of Spanish from her nanny, her dad quickly put an end to it. His wife didn’t know that he had told the nanny to only speak to the child in English, and she wondered why he’d do that.
More info: Reddit