( ( ( The ( principal types ) ) ( of ( chemical bond ) ) ) ( ( are ( ( the ionic ) ( , ( covalent ( , ( metallic ( , ( and ( hydrogen bonds ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ principal) (NNS types)) (PP (IN of) (NP (NN chemical) (NN bond)))) (VP (VBP are) (UCP (NP (DT the) (NN ionic)) (, ,) (ADJP (JJ covalent)) (, ,) (ADJP (JJ metallic)) (, ,) (CC and) (NP (NN hydrogen) (NNS bonds)))) (. .)))
The principal types of chemical bond are the ionic, covalent, metallic, and hydrogen bonds.
(ROOT (S (NP (NN Hydrogen) (NN chloride)) (VP (VBZ is) (NP (DT a) (JJ covalent) (NN compound))) (. .)))