Well, let us leave it. 
( Well ( , ( ( let ( us ( leave it ) ) ) . ) ) )
(ROOT (S (INTJ (UH Well)) (, ,) (VP (VB let) (S (NP (PRP us)) (VP (VB leave) (NP (PRP it))))) (. .)))
Let's leave it.
( ( Let 's ) ( ( leave it ) . ) )
(ROOT (S (NP (NNP Let) (POS 's)) (VP (VBP leave) (NP (PRP it))) (. .)))