with my kids i made them read out loud. it helps to hear what words they are struggling on and when they are you are there to help them.
also it helps to have them read out loud, some people do better to hear what they are saying to help in memory, just because you read it does not mean u will remember it, if you read it and hear it its more of a repeat thing over and over and your mind tends to remember in more than one way.  if you try to make him read out loud he will know you are interested, always start with encouraging and reward with such things. when your child struggles say, thats great sound it out with me let you child think they are teaching you, if you go in say no no no its this or that or like this or like that they feel as if they failed. help with sounding it out with them break the words into smaller words if you have to break the word into small letter sounds so they add one letter at a time. that way they feel like a king or queen when they succeed. plus they also know mommy has all the help when they need it but remind them that they did it. children need tons of encouragement!!!

good luck!

ps with my son it took us weeks to perfect the struggling and sounding out theory, so i hope it helps you. i know with my oldest child he is always worried about everyone else, if he sees your frustation he cant focus on the task at hand which in turn makes you more frustrated, try to learn together, it creates a bond that is unbreakable!