somebody was thought to do/ have done.句型中,何时用to do,何时have do

somebody was thought to do/ have done.句型中,何时用to do,何时have do 何时用apear to do,何时用apear to have done?分别要是什么时态背景?请举例说明, was to do&was to have done 歌曲中含有TO DO ：TO BE DONE ：TO HAVE BEEN DONE ：TO HAVE DONE seem to do seem to have done to do 和 to have done 句首做主语何时用doing 何时用to do have done nothing but do 、done 、doing、to do? have problem done/doing/to do 句首何时用doing、to do 、do . 英语中have的用法have to do have sth do have sth done有什么区别?有没有have 表愿望未达成是was to do还是was to have done