I think the doctor is able to care of whatever is the matter with your son.
这里的whatever能否改为what？即of 后是what引导的名词性从句。
I think the doctor is able to care of whatever is the matter with your son.
不需要替换。其实，whatever 和 what 都可以引导名词性从句。具体说，它们引导的都是名词性关系分句。不同是，前者具备强调意义：
whatever = anything that
what = the thing that
句子有错误，即：care 是不是为 cure 之误？请查原句是不是还有错误。
