I have a problem with my 4 year old boy. He doesn't talk much, and when he does it's two words at a time. He is not Autistic, and he doesn't have a mental problem. He just won't talk much. He knows his ABC's and sings them when he wants too but not when I or someone else asks. He's enrolled in preschool, and he is working with a speech pathologist. So I guess my question is what else can I do for him?:(

Maybe Music or Television, could help.
My Granddaughter, when I would ask her to say "California" or any word, she would not say it, So I would say "Don't say california", She would say California. Then I would say"Don't say Mississippi", she would say Mississippi.
Kids are funny. If you are ask him if he wants milk. Don't let it be a yes or no question.
Ask, "Do you want Milk or Juice?" to make him say other than yes or no.
It could be he is shy.

How does he work with other kids?

My son is 4 and always seemed to be a little "behind" in his speech... mostly he mumbles words a lot. Its hard to understand him. The speech therapist said his mouth can't keep up with his brain... he has the ability to say many words carefully, or make noises that will lead to success in certain sounds, he just doesn't.

Seems to me that when he is around other people and kids, his speech improves. So outside of school, does he get any other "kid contact"... or even contact with other people who play with him? For better or worse, my kid often learns new words and phrases from other kids with great enthusiasm.

The day I told him someday he could have a cool skateboard and he corrected me by saying, "no... a super power ranger shooter flying skateboard", having never seen them on TV, was telling.

As much as I read to him and we get new books from the library all the time, and as much as I engage him in converstation, a lot of his excitement about conversation comes from the playground, classroom, and playdates.

Maybe try some interactive videos, like sing-along videos or something that will get him talking. Try reading to him, encourage him to play with other kids. The speech pathologist will probably continue to help him. My friend's son had the same thing when he was that age, once he was in 1st grade and in school all day, he started talking much more. Good luck!

Encouragement, encouragement, encouragement! Never utter a word to your son in frustration or anger and never punish him for his lack of communication. Instead, lead by example. Speak to him in a moderate speed using different tones and inflections. When he says "milk" and ends his 'sentence', ask him "what about milk?" Don't belittle him, simply let it be known that you are unsure what he wants you to know about milk. Don't ask if he wants milk, let him express it. Play dumb when it comes to small things like that. Of course those rules don't apply when there is an emergency or true need for something. Read books every day. Books your child is interested in. The truth is your child probably understands speech far better than you think and just isn't actively demonstrating it. When you read, ask questions like, where do you think X is going? How do you think he will get there? Would you want to do that too? Ask anything that requires a response. Over time your child will be able to get more detailed and descriptive. Also, I suggest being careful about which shows your son watches on TV. For example, the Disney cartoon Max and Ruby is pretty good for a child first learning to speak... however because Max is a main character who usually says no more than one word at a time, the show can also subconsciously create a "single word" speech pattern for a child. (I learned this the hard way and eventually had to ban the show from my home.) Most of all just try to be patient. Trust in the speech therapist and be sure to pay attention to your son every time he speaks a full sentence. Reward his effort by continuing the conversation. Try not to get frustrated, it will all work out in the end.

Noggin and Sprout are good stations for kids. He will be singing along in no time.

Remember... einstein and edison didn't talk until they were REALLY old. And they turned out OK.

I only say this because I didn't start talking until I was about 6. I knew how to talk.. I just didn't feel like it.

I agree with Isneeze if he doesn't have any physical, mental or hearing problems then
He may just not feel he has anything to say. One more thing you can try is don't cater to him.
In other words, if he wants a cookie, drink, toy, etc... make him learn to ask for it rather than seeing he wants it and handing it to him before he gets to ask.

Try playing interactive games with him, where he has to answer you back. Make a game out of picking up toys or what clothes are. Hold up a shirt and ask him, what is this... if he answers make a big deal out of it. Clap, give him a hug, tell him he did a good job. That will encourage him to answer you more. I also agree that maybe he just isn't ready to talk yet. Children are funny and they will do everything in their own time.