At the same moment I felt a terrific blow on the back of my head… ." She shuddered.
( ( ( ( ( ( At ( the ( same moment ) ) ) ( I ( ( felt ( a ( terrific blow ) ) ) ( on ( ( the back ) ( ( of ( my head ) ) ... ) ) ) ) ) ) . ) '' ) ( She shuddered ) ) . )
(ROOT (S (S (PP (IN At) (NP (DT the) (JJ same) (NN moment))) (NP (PRP I)) (VP (VBD felt) (NP (DT a) (JJ terrific) (NN blow)) (PP (IN on) (NP (NP (DT the) (NN back)) (PP (IN of) (NP (PRP$ my) (NN head)) (: ...)))))) (. .) ('' '') (S (NP (PRP She)) (VP (VBD shuddered))) (. .)))
I was hit on by a nerdy guy at the local bar. 
( I ( ( was ( hit ( on ( by ( ( a ( nerdy guy ) ) ( at ( the ( local bar ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBD was) (VP (VBN hit) (PP (IN on) (IN by) (NP (NP (DT a) (JJ nerdy) (NN guy)) (PP (IN at) (NP (DT the) (JJ local) (NN bar))))))) (. .)))