Cat

I taught my cat to understand "No" Everytime he does something wrong... I simply greet him with a firm "No" without any other comments. You tell him "No" and pick him up off the couch and put him on the floor. You will need to do this several times because cats are very stubborn and have a mind of their own. They hate to be told what to do. If it is a kitten... don't yield at him or try to scare him... otherwise he will be scare of you for the rest of his life and he won't be a friendly cat. With the litter box... it is the same process. While he is a kitten... you need to keep an eye on him... just like you would do with a child. When cats have to go... you can tell... because they start looking around and sniffing to find a spot. As soon as you see him doing that... you pick him up and put him in his litter box. You have to clean his litter box every single day. If it is dirty or smelly... he won't go in it. You need to wash it with detergent everytime to get the smell out. Note that cats are not like dogs... particulary when they are kitten. Calling them does not do the trick. You have to pick them up and take them there. Cats will only come to you if they feel like it... never because you want them to.

I don't keep my cats off the couch, they are allowed to sleep on it. If you think your couch will get dirty, try putting a little rug there for the cat to sleep on. If he tries sleeping elsewhere on the couch, just move him back to the rug. He will soon ge the idea. As for using litter trays; put him on it regularly, whether he uses it or not. If yoiu see him about to do a wee or poo, quickly pick him up & put him on the litter tray. Cats learn to use litter trays easily. Wait until he starts scratching the couch!!

my suggestion is, put them in a warm place, it will be good if inside a litterbox and put a blanket to keep them warm. Cats really like couch because it is warm, they always like warm places, so sometimes they sleep beside you, they want to keep their body warm. when you see them going on the couch, put them urgently on the litterbox so they will not get used to the couch and avoid it.