New language
A : What's the matter?

B :  -  I have a stomachache.
              -  I have a cold. I'm sneezing.
              -  You have a sore throat and a fever.
              -  I have a toothache.
              -  My knee hurts.
            -  I am sick.

Problems and advice
   1.        A : What's the matter with you?
               B : I have a terrible headache.
               A : Take some aspirin.

       2.  A : What's the matter with them?
               B : They have a stomachache.
               A : Take some medicine. Don't eat anything.
       
    3.  A : What's the matter with him?
         B : He has a toothache.
           A : Go to see the dentist.