Show him that you are responsible by doing your chores and homework. Don't leave things til the last minute. You need to be able to teach the dog and take care of it. So maybe you should do some research on dog care or check some books out at the library. If he believes that you are capable of taking care of the dog then you may be in luck. It's hard work taking care of a dog and it costs a pretty good amount of money for food and vet bills. Also don't keep asking every hour of every day-I know it's tempting but it will just annoy him. If you research dog care and stuff like that it will show your dad that you are serious about it too. I hope you get one soon!!! Good luck!