( ( ( The ( vast majority ) ) ( of ( HIV infections ) ) ) ( ( ( are sexually ) transmitted ) . ) )
(ROOT (S (NP (NP (DT The) (JJ vast) (NN majority)) (PP (IN of) (NP (NN HIV) (NNS infections)))) (VP (VBP are) (ADVP (RB sexually)) (VP (VBN transmitted))) (. .)))
The vast majority of HIV infections are sexually transmitted.
(ROOT (S (NP (NP (DT The) (JJ vast) (NN majority)) (PP (IN of) (NP (NN fish)))) (VP (VB reproduce) (ADVP (RB sexually))) (. .)))