( ( In ( covalent bonding ) ) ( , ( electrons ( ( are shared ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (JJ covalent) (NN bonding))) (, ,) (NP (NNS electrons)) (VP (VBP are) (VP (VBN shared))) (. .)))
In covalent bonding, electrons are shared.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NNS electrons)) (VP (VBP are) (VP (VBN shared) (ADVP (RB equally)))))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN called) (NP (NN nonpolar) (NNS bonds)))) (. .)))