If your child has begun using a particular swear word, then it's important to speak to him about it rather than ignore his behaviour. Your child may not fully understand a swear word's meaning but children do understand that certain words can hurt or offend others.
How you react will influence whether your child swears again. It's important that you remain calm and explain clearly that the word your child has just used is not acceptable. This will help to prevent him using swear words in the future.
Should I explain the meaning of the word?
If you feel your child may have a general understanding of the word, you can ask her what she thinks it means and then use general terms to explain why it's inappropriate. For instance, you could say, 'that is a word for private body parts, in this family we don't use that word'.
Practice what you preach. If you swear a lot, it is unrealistic to expect your child to avoid swear words. So avoid swearing, or at least swearing in front of your child!
If your child has decided to say a particularly bad swear word over and over again, you need to be decisive. Simply tell your child that that is not a word he or she is allowed to use, and that you will have to give him or her a time out if you hear it again.
Not allowing swearing to get attention, and teaching your child that harsh words can hurt feelings is the best way to get your child to stop using swear words to gain attention.