The man looked at the girl.
( ( The man ) ( ( looked ( at ( the girl ) ) ) . ) )
(ROOT (S (NP (DT The) (NN man)) (VP (VBD looked) (PP (IN at) (NP (DT the) (NN girl)))) (. .)))
A man and a girl were in sight of each other. 
( ( ( ( A man ) and ) ( a girl ) ) ( ( were ( in ( sight ( of ( each other ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN man)) (CC and) (NP (DT a) (NN girl))) (VP (VBD were) (PP (IN in) (NP (NP (NN sight)) (PP (IN of) (NP (DT each) (JJ other)))))) (. .)))