it is +adj.+（for sb.）to do sth。
difficult作为一个形容词,后面应该跟to do形式。
翻译成（对某人来说）做某事怎么样。
例句
It was a rather difficult question.
这是个相当难的问题。
It was a difficult birth.
那是一次难产。
It was rather a difficult question.
这真是个难题。
She made life very difficult for me.
她使我的生活变得很艰难。
