what'll be = what will be 的缩写
what will be difficult 是从句
what will be difficult is getting him to ...
意思是
不容易的是要他去（做某事）
what'll be是神马句式
what'll be = what will be 的缩写
what will be difficult 是从句
what will be difficult is getting him to ...
意思是
不容易的是要他去（做某事）