difficult for sb to do sth 和difficult for sb doing sth 有什么区别?tell sb to do sth 和tell sb doing sth 有什么区别?

是be difficult to sb 还是be difficult for sb? be difficult to sb还是 be difficult for sb.? 到底该用哪个介词啊? difficult for sb to do sth 和difficult for sb doing sth 有什么区别?tell sb to do sth 和tell sb doing sth 有什么区别? it is difficult for sb to 和 make sb hard to do sth 有什么区别? it is so difficult for sb to do sth,difficult用so形容对吗? make it difficult for sb to do有这样句式吗? make it difficult for sb to do...最好配个例子方便我理解. 动词不定式的逻辑主语for sb是作状语吗?例：It's a difficult question for you to answer.It's hard for you to learn.您的意思是for sb/of sb都是作状语吗？ it 形容词 for sb to do sth,有这个句式吗有一个句子叫“I found it difficult for me to do the physics problem. be useful to sb还是for sb? be embarrassing to sb还是for sb? be important to sb还是for sb write for sb还是write to sb get sth for sb还是to sb? sth to sb 还是 sth for sb express sth for sb 还是to sb be rude to sb还是for sb best wishes to sb or for sb