Hello All,
You have to understand as a parent that children in this day and age will learn swear words from an incredibly young age, their learn these from all different surroundings but mostly from kindergarten or school.
Just say this to the child it worked for me...
" WOW, thats a new word, where did you hear that?"
" I know you know these words and thats absolutly fine, however Mummy would prefer it if you didn't use them. Although it's fine for you to know them"
"When you say that you have a dirty mouth and you don't look very nice, how about we just know these words but never use them as it's better to have aclean mouth than a dirty one"
The important thing is to never laugh or give any good attention for swearing. Everytime a swear word is used it should be dealt with straight away and not just on the odd occasion.
By telling them it is ok for them to know them but not speak them is giving them a little control. This will stop them using it as a 'getting back at you' tactic, since you have said it is OK to know them. They will realise/think it's not that much of a big deal and the swearing to start to stop since you are not give this massive reaction to it.
The other thing is not to swear yourself as this can sometimes be the main reason for them starting. However if you do let one slip always acknowledge it yourself and tell yourself off for doing it in front of the child. Many times the child will join in and say "Mummy you have got a dirty mouth" and then start to feel proud hat they are sort of helping mummy out to.
Sorry it's long winded, hope you got the point I am trying to make.
Regards