Although this sounds counter intuitive, read on and all will be revealed.
This will be a repetition and reward sequence. Choose the word you want to have your dog react to when you want him to bark e.g. "Talk".
The first step is for your dog to link your command with his barking. Hold up a treat and say, "Talk"
Eventually your will bark if only to 'encourage' you to drop the treat.
Say "Good Dog" and give him the treat.
Do this twice a day for at least 5 minutes until your dog has learned to bark when you say "Talk".
Gradually start saying "Talk" without always giving a treat but with lots of praise and petting as that is itself a reward.
Using a treat infrequently will train your dog faster because you are using "intermittent reinforcement". It's a very powerful technique because your dog will perform the way you want as they continually hope for that unpredictable treat.
This works just as well on humans. Casinos rely on it for their profits on the slot machines as do golf courses as golfers hit an occasional good shot that keeps them coming back (OK that's a bit of a stretch but that's what it feels like).
Intermittent reinforcement at its best can easily be seen when you feed a begging animal at the table Your pet will keep on begging even if you stop as they know that once in a great while their begging works.
Step 2 Train your dog not to bark
Now you want to train the dog to stop barking. Again choose the word you want to have your dog react to when you want him to stop barking bark e.g. "Quiet".
The key is to ALWAYS use the same word.
The process is pretty much the same as "Quiet" but adds a layer. Start by having him "Quiet" once he barks, hold up a treat and say "Quiet". Wait until he stops barking, then say "Good Dog", let him have the treat and pet him.
Do this twice a day for at least 5 minutes until your dog has learned to be quiet on your command.
Again you gradually reduce the treat level while keeping the praise and petting.
Applying the Training
Now when the dog barks at other things, use "Quiet" and "Good Dog" as in training. Again consistency is key. Correct your dog at EVERY bark.
You can now branch out...does your dog bark when people come to the door? If so have someone repeatedly come to the door and use the "Quiet" command. Use treats, praise and petting when you get the desired quiet response.
You can use this technique so the dog doesn't bark when he's alone or if he's in the car etc etc etc.
Eventually you won't need treats as 'Good dog" will be reward in itself but the praise must stay. Give treats sparingly.
If training fails
A good pro-trainer is a good solution for people who can't train their dogs. Realize that a good part of this process will be training you! Check references and professional credentials. Ask about his methods and see if you agree with them.
