American men don't cry because it is considered not characteristic of men to do sobecause it（ 形式主语） is considered （ 谓语） not characteristic （ 主语补足语）of men（动词不定式逻辑主语） to do s...也就是说，如果划分句子成分的话，是把men to do so划在一起？of men是说明characteristic的。 主语 就是不定式 to do so就好比 It is very kind of youtohelp me .