Poirot answered them categorically, almost mechanically. 
( ( ( ( Poirot ( ( answered them ) categorically ) ) , ) ( almost mechanically ) ) . )
(ROOT (S (S (NP (NNP Poirot)) (VP (VBD answered) (NP (PRP them)) (ADVP (RB categorically)))) (, ,) (FRAG (ADJP (RB almost) (RB mechanically))) (. .)))
Poirot gave them the answers in perfect order, like a robot.
( Poirot ( ( ( gave them ) ( ( ( ( the answers ) ( in ( perfect order ) ) ) , ) ( like ( a robot ) ) ) ) . ) )
(ROOT (S (NP (NNP Poirot)) (VP (VBD gave) (NP (PRP them)) (NP (NP (DT the) (NNS answers)) (PP (IN in) (NP (JJ perfect) (NN order))) (, ,) (PP (IN like) (NP (DT a) (NN robot))))) (. .)))