I am a professional pet trainer. This actually isn't a difficult problem to fix, if you're willing to take a few simple steps.

First off: Cats scratch because it feels really good! It helps sharpen their claws by removing the outer layers of keratin. It also stretches their spine and all their muscles, down to the tips of their toes. Many people believe their cat does this to spite them, but it's simply untrue. Scratching is a normal behavior for cats, just like chewing is for dogs. If you provide good alternatives for your cat to scratch, he'll never scratch your carpet or furniture.

1. Buy several different kinds of scratchers. I recommend you try a few of the following:

A tall carpeted post (tall enough that the cat can fully stretch when standing on her hind legs -- about 36" tall.) A berber (short loop) carpeted scratcher (scroll, incline, or arch-shaped.) A flat or cone-shaped cardboard scratcher. A sea-grass or rope scratcher. Cat furniture for climbing and stretching.

This is to audition different materials and find out what your cat likes best. We want to find a substitute that he likes as much --or preferably better than-- furniture, or he will choose to scratch furniture.

1. Put the scratchers directly in front of the furniture where she likes to scratch. Most cats like to scratch when they first wake up, so I bet she has a few different spots around the house where you should be stationing scratchers. Having a scratcher or two in every room would not be overkill if the problem is as extensive as your post suggests.

For example: If she likes to scratch the arm of an armchair, put the scratcher directly in front of it.

1. Purchase catnip oil spray (I like the Kong brand best; try to get the pure catnip oil rather than oil diluted with water) for about $6 per bottle. Spray it on the scratchers to make them more enticing. This is my favorite trick because it usually causes them to start scratching right away. If he scratches, praise and reward him profusely (more on this in step 5.)

2. Play with your cat on or near the scratchers to get him comfortable with them.

3. If you catch your cat scratching on furniture, don't scold him; just pick him up and place him in front of the post. If he scratches the post, praise him and give him a "jackpot" reward. This could be several favorite treats, a small piece of cheese or chicken, etc. If you don't have the food with you, start praising him (i.e. "What a smart boy Simon is! What a good kitty! It makes me so happy when you use your post!") and run directly to the fridge for his treat. Continuing to praise him connects the behavior (post scratching) with the reward (eating cheese.)

4. My cats liked it when I "modeled" scratching the post for them by scratching it with my fingernails, but this will not work for every cat.

Once your cat is reliably scratching the posts, and has not scratched furniture in over 2 weeks, you can move the posts to less obtrusive locations (i.e. against a wall rather than in front of the chair.) You may be able to get rid of SOME of the posts, but you cannot get rid of all the posts. Try to keep one in each room where your cat regularly sleeps.