How to punish a 2yo

I have a 5yo and a 2yo. As the 2yo gets older he's starting to listen less and get slightly more, um, mouthy? Like saying "NO" over and over and crying the moment you say "stop" or "no" when he's doing something. Things were different when our 5yo was an only child. He acted completely different so we are not used to this. I don't know how to punish a 2yo at all as he seems to just not fully understand at all that he did something he's not supposed to. Any suggestions?A couple things to know: First, I don't spank. I will give a swat on the butt but I don't believe in spanking or smacking in the face. Right or wrong in what people believe that's the choice my wife and I have made. Second. I have way more parenting questions after this one is answered so I'm sorry if I show up a few times.Also, I get grief sometimes when I ask people for advice. Mostly I hear "we're not going to tell you how to parent" and the such. I'm not asking people to tell me how to parent. I'm asking for advice. I take that advice and read it and then decide how I'll proceed in whatever the matter is. Also I am a firm believer in it takes more than just the parents to raise a child. I'm sorry if this post is too long and if it is, kindly say that in the comments and explain why so I can learn how to post here. But please, that doesn't mean everyone tell me to shut up lol. Thank you via /r/Parenting https://ift.tt/2FzlkZ6