Alissa G. answered 03/29/19
Writing Coach: High School, College, Grad, ESL Students, Professionals
Hi! This is a really neat question. I would say that the main difference I immediately notice between the examples you gave is that the first two are sentences that end on an adjective, versus the second two examples, which have either a relative pronoun or preposition following the adjective to connect the first clause to the second part of the sentence.
In other words, "I am very much afraid that... (relative pronoun) = Clause 1
...she is not going to arrive on time" = Clause 2
I can't say for sure if I am 100% correct about this, but that is simply what I can see is apparent in your examples. Hopefully other tutors can provide insight as well!
-Alissa