Does “no” work with your baby?

J

My 13-month old has really been testing my patience. He seems to understand “no”-I have even seen him cry if someone says it a bit sharply or loudly. That being said, If I am the one saying it, he laughs, and then continues doing what he is doing that he shouldn’t be. I have tried saying it softly, loudly, kindly, meanly, with different facial expressions-nothing seems to work! Does your baby understand “no” and do they take you seriously? Anyone have any insight or advice?!