They were inferior.
( They ( ( were inferior ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBD were) (ADJP (JJ inferior))) (. .)))
They were inferior because they lacked knowledge.
( They ( ( ( were inferior ) ( because ( they ( lacked knowledge ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBD were) (ADJP (JJ inferior)) (SBAR (IN because) (S (NP (PRP they)) (VP (VBD lacked) (NP (NN knowledge)))))) (. .)))