( There ( ( are ( ( three ( main types ) ) ( of ( galaxies ( based ( on ( their shape ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD three) (JJ main) (NNS types)) (PP (IN of) (NP (NP (NNS galaxies)) (VP (VBN based) (PP (IN on) (NP (PRP$ their) (NN shape)))))))) (. .)))
There are three main types of galaxies based on their shape.
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD three) (NNS types)) (PP (IN of) (NP (NNS galaxies))))) (. .)))