he is very busy

Question

he is very busy(writing)his papers.he is far too busy（to receive）callers
busy后面只能加doing的形式吗?那后面的空为什么是to do的形式呢?求讲解

Answer 1

be busy doing sth忙于做某事
be busy with sth忙于某事
too+adj/adv to do sth 太（怎么样）而无法做某事
He is far too busy（to receive）callers.
他太忙了,而无法接电话.