It is amazing what toddlers pick up. They can hear a word once and start to use it, especially if they realize that it gets a big reaction from their mommy or daddy. My advice with potty mouthed toddlers would be don’t give it any energy. You can explain to him that some words have stronger meaning than others and just like certain behavior some words are inappropriate. I believe that if you make a big deal about it, for example, using time outs if he says it or reacting negatively he is likely to say it more. He doesn’t understand the meaning but he does understand the reaction and strong energy it is evoking in you.
I would also let your friends/family know about your son’s new vocabulary and suggest that they should try and curb their language around him, as he seems to be picking up on some colorful words. Every family member can support you in this stage. Just the other day my 4 year-old granddaughter said to her 3 year-old cousin, my grandson, “We don’t say that word, that’s ‘potty talk’.”
We are always reminded at these times how important we are as role models to our little ones who will often mirror what they see, hear and feel.