Introductory it as Subject
Pattern group 6: it V adj clause
There are seven patterns in this group, each consisting of it, the verb, an adjective group, and a type of clause. Patterns 6.6 and 6.7 have a prepositional phrase as well.6.1 it V adj that
It seems likely that she will leave soon.6.2 it V adj to-inf
It is difficult to see in the dark.6.3 it V adj wh
It became apparent how ill she was.6.4 it V adj when/if
It is nice when people compliment you.6.5 it V adj -ing
It is interesting seeing what happens here.6.6 it V adj of n to-inf
It's nice of you to come.6.7 it V adj for n to-inf
It is impossible for me to arrive any earlier.