My Samsung tablet keeps freezing

I have a Samsung galaxy tab 4 7.0 and it was working great for a month but one day it froze and I had to force restart it. Then it kept freezing in one hour of me playing on my tab it wold freeze 2 times and I have to force restart it. One other thing if I Leave my tablet frozen for a while and not force restarting it, a message would come up saying touchwiz has stopped working. This is pretty a noting and I think it may be a corrupt SD card but I don't know how to tell if it's corrupt . I search all over but couldn't find an answer. Thank you