I guess I had a friend staying overnight.
( I ( ( guess ( I ( had ( ( a friend ) ( staying overnight ) ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP guess) (SBAR (S (NP (PRP I)) (VP (VBD had) (NP (NP (DT a) (NN friend)) (VP (VBG staying) (ADVP (RB overnight)))))))) (. .)))
I suppose my friend stayed until morning. 
( I ( ( suppose ( ( my friend ) ( stayed ( until morning ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP suppose) (SBAR (S (NP (PRP$ my) (NN friend)) (VP (VBD stayed) (PP (IN until) (NP (NN morning))))))) (. .)))