( ( An ( electrical insulator ) ) ( ( is ( ( a material ) ( that ( ( ( will not ) easily ) ( conduct ( an ( electric current ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT An) (JJ electrical) (NN insulator)) (VP (VBZ is) (NP (NP (DT a) (NN material)) (SBAR (WHNP (WDT that)) (S (VP (MD will) (RB not) (ADVP (RB easily)) (VP (VB conduct) (NP (DT an) (JJ electric) (NN current)))))))) (. .)))
An electrical insulator is a material that will not easily conduct an electric current.
(ROOT (S (NP (PRP You)) (VP (VBP call) (NP (NP (NNS materials)) (SBAR (WHNP (WDT that)) (S (VP (VBP have) (NP (JJ high) (NN resistance)) (PP (TO to) (NP (JJ electric) (JJ current) (JJ electric) (NNS insulators)))))))) (. .)))