sb can not only do sth but also do sth这种结构是都正确?

sb can not only do sth but also do sth这种结构是都正确? let sb.do sth.该否定句是let sb.not do sth.还是let sb.not to do sth let sb not do sth not only like will for sb .To do STH . 是ask sb not to do sth 还是ask sb to not do sth 是tell sb.not do sth.还是tell sb.not to do sth.那么ask呢? 用whant to do sth,try to do ,there be,not.but...,take sb sth, hope sb.to do sth这个短语结构正确吗 can't but do sth 为什么ask sb to do sth的否定形式是ask sb not to do sth 为什么是let sb not do sth而不是let sb don't do sth? 用tell sth.tell sb.sth.tell sb.to do sth.tellsb.not to do sth