Please look into having your school district give your a son a complete and indepth speech test, looking specifically at any type of dyslexia or speech impairment/learning difficulty having to do with language. It definitely sounds like your son has an issue with words/language. Language is so important to a good life and a good job; I'd say even more important than math skills.
As a mother with a daughter who started speech lessons when she was 3 (and will have them yet when she's in 6th grade next year), was in Early Childhood class as well as OT/PT when she was 4 for hypotonia (and finished OT/PT after 4th grade), as well as taking a special reading class when she was in 1st grade, any and all help you give your son when he's young will make all the difference to how he does academically in school. Now in the 5th grade, my daughter reads two grade levels above her grade level and her comprehension is excellent. We still have to work on her pronunciation. But she absolutely loves reading, whether quietly to herself or out loud to me at night before bed.
Do you have any computer games that are language based? I had my daughter do those all the while she grew up, as well as math. I feel that her "playing" games where she had to use her words and math have really, really helped her. She has a few problem areas in math; the other day, she asked me to load a math game so that she could work on her math!
Making learning fun might be one way to get your son excited or at least interested in reading. But if he actually has issues with comprehension or the way the sentence reads (do the words or letters "rearrange" themselves when he's trying to read?) or trying to "sound out" letters and words, then you need to find out what areas he is having problems with so he can get help.
Good luck.