曹老师提到（http://ask.yygrammar.com/q-26040.html），

Use too many with countables to talk about more things than necessary or possible.中的than从句=than are necessary or possible（than为主语，对应但不等同于主句的things)

He never says more than is necessary.无省略，than为主语，它的意思对应于主句中的more（只是对应不是等同）

我的疑问：

表语为 possible时，主语一般是形式主语it,很少是具体的事物.这里的things应是具体的事物。

表语为 necessary时，主语一般是形式主语it,偶尔见到是具体的事物。

是不是也可以这样补全：

Use too many with countables to talk about more things than necessary or possible.

=than it is necessary or possible to talk about.

He never says more than is necessary.
=than it is necessary that he say.
=than it is necessary for him to say.

 以上只是我的一孔之见，请老师指正。