( ( A ( plane mirror ) ) ( ( ( will always ) ( produce ( a ( virtual image ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN plane) (NN mirror)) (VP (MD will) (ADVP (RB always)) (VP (VB produce) (NP (DT a) (JJ virtual) (NN image)))) (. .)))
A plane mirror will always produce a virtual image.
(ROOT (S (NP (DT A) (NN plane) (NN mirror)) (VP (VP (VBZ has) (NP (DT a) (ADJP (JJ flat) (JJ reflective)) (NN surface))) (CC and) (VP (VBZ forms) (NP (RB only) (JJ virtual) (NNS images)))) (. .)))