How should a parent react when a pre-schooler (age 3) repeats a swear word again and again that she heard from who knows where?
Isn't it wonderful how quickly children learn about the power of words! This is actually an easy problem to solve. First, keep in mind that your daughter probably has no idea what the word means. Second, she's using it because it gets an emotional reaction from the adults around her. In other words, it gives her power. The only thing you have to do is ignore her when she uses that word. Don't say anything positive or negative. Don't become upset. Simply ignore her. She won't like that at all. In fact, she might try using that word several times in a row. Just keep ignoring her. Then pay attention to her when she says something polite. She'll soon learn that she has more power when she talks to you politely. That should solve the problem -- at least for the next year or two.