yep because it's when it's self propelled it's heavy yeah
( yep ( because ( it ( 's ( when ( ( ( it 's ) self ) ( propelled ( it ( 's ( heavy yeah ) ) ) ) ) ) ) ) ) )
(ROOT (S (VP (VB yep) (SBAR (IN because) (S (NP (PRP it)) (VP (VBZ 's) (SBAR (WHADVP (WRB when)) (S (NP (NP (PRP it) (POS 's)) (NN self)) (VP (VBD propelled) (SBAR (S (NP (PRP it)) (VP (VBZ 's) (NP (JJ heavy) (NN yeah))))))))))))))
it's heavy when it's self propelled
( it ( ( 's heavy ) ( when ( ( ( it 's ) self ) propelled ) ) ) )
(ROOT (S (NP (PRP it)) (VP (VBZ 's) (ADJP (JJ heavy)) (SBAR (WHADVP (WRB when)) (S (NP (NP (PRP it) (POS 's)) (NN self)) (VP (VBD propelled)))))))