( Helium ( ( ( ( is ( an ( inert gas ) ) ) and ) ( ( ( does not ) easily ) ( combine ( with ( other elements ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Helium)) (VP (VP (VBZ is) (NP (DT an) (JJ inert) (NN gas))) (CC and) (VP (VBZ does) (RB not) (ADVP (RB easily)) (VP (VB combine) (PP (IN with) (NP (JJ other) (NNS elements)))))) (. .)))
Helium is an inert gas and does not easily combine with other elements.
(ROOT (S (NP (JJ Reactive) (NNS elements)) (VP (VBP are) (ADJP (JJ able) (S (VP (TO to) (VP (VB combine) (ADVP (RBR more) (RB easily)) (PP (IN with) (NP (JJ other) (NNS elements)))))))) (. .)))