( ( Elements ( that ( are ( ( nonmetals , ) ( such ( as ( ( ( ( ( hydrogen , ) carbon ) , ) and ) oxygen ) ) ) ) ) ) ) ( ( ( combine ( with ( each other ) ) ) ( to ( from ( covalent compounds ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Elements)) (SBAR (WHNP (WDT that)) (S (VP (VBP are) (NP (NP (NNS nonmetals)) (, ,) (PP (JJ such) (IN as) (NP (NP (NN hydrogen)) (, ,) (NP (NN carbon)) (, ,) (CC and) (NP (NN oxygen))))))))) (VP (VBP combine) (PP (IN with) (NP (DT each) (JJ other))) (PP (TO to) (PP (IN from) (NP (JJ covalent) (NNS compounds))))) (. .)))
Elements that are nonmetals, such as hydrogen, carbon, and oxygen combine with each other to from covalent compounds.
(ROOT (S (NP (NN Hydrogen) (NN chloride)) (VP (VBZ is) (NP (DT a) (JJ covalent) (NN compound))) (. .)))