I think that was kind of hard for him, you know.
( ( I ( think ( that ( was ( ( kind of ) ( hard ( for him ) ) ) ) ) ) ) ( , ( you ( know . ) ) ) )
(ROOT (S (S (NP (PRP I)) (VP (VBP think) (SBAR (IN that) (S (VP (VBD was) (ADJP (ADVP (NN kind) (IN of)) (JJ hard) (PP (IN for) (NP (PRP him))))))))) (, ,) (NP (PRP you)) (VP (VBP know)) (. .)))
That must have been difficult for him.
( That ( ( must ( have ( ( been difficult ) ( for him ) ) ) ) . ) )
(ROOT (S (NP (DT That)) (VP (MD must) (VP (VB have) (VP (VBN been) (ADJP (JJ difficult)) (PP (IN for) (NP (PRP him)))))) (. .)))