Yeah Tash, I guess all babies are alittle different, but I'd say Charlotte learnt what "no" meant when she started repeating it back to me.I actually started to teach her, not so much NO, but "Be nice", and "Be Gentle", That started with a bunchof flowers i had on a low coffee table, when she was about 8-9 months old, and instead of having to put them up, i just thought i should teach her that yes she can look, and have a little touch, but just be gentle.... and i would sit there with her and show her how to be gentle.  

I would take her hand and show her how, I figure, if its down and they can reach it, you may as well make life easier on yourself. And also on them as well because i am sure they get sick of hearing "no". Good Luck

~ Courtney

well i have been saying no to my bubs for a few months now she is almost 1 i think she started getting the picture and changed just no to NO!! in a stern strong voice i think she wasnt sure but new oh ok and just stops in her tracks well most of the time lol good luck just keep trying

~ Rhi

I started saying no to Ruby when she was about 7 months and by about nine months she not only knew the meaning but was also repeating it. And as one of the other girls said if u use a different voice bubs will soon get the picture! Hope that helped

~ Anouska

My daughter was about 9 mnths when she learnt what "no" meant, and i could tell cos she would hesitate to do whatever she wasnt meant to. You will notice if she can understand, as she will stop and listen or something.

~ Alyce

I started teaching my son no just as he was starting to crawl and grab things. He started to understand it at about 6 months if i see him look at something (our dvd stand) he looks at me then makes a run for it as soon as i say no he stops and turns around - sometimes he tests me all day but most of the time his fine. His now 1 and knows not to go near the dvd stand and a few other things.

Your little bub will understand it eventually just keep it up your doing great - also make sure when you say it he knows your talking to him maybe get down to his level and look him in the eyes and say NO sternly then gradually make your way futhur back until he understands. I think it's best to teach them early like you are because whenever you go into a shop you know they will listen to you.

Good luck!

~ Jenni