I have a fever.He/She has a fever.
I hurt my leg.He/She hurts his leg.
I have a cold.He/She has a cold.
I have a toothache.He/She has a toothache.
I have a hadache.He/She has a headache.
I have a sore throat.He/She has a sore throat.
另外,第一人称的we和第三人称的they用法跟第一人称的I 一样.