Kill chickens.
( ( Kill chickens ) . )
(ROOT (S (VP (VB Kill) (NP (NNS chickens))) (. .)))
Use a knife to kill the chickens.
( ( Use ( a ( knife ( to ( kill ( the chickens ) ) ) ) ) ) . )
(ROOT (S (VP (VB Use) (NP (DT a) (NN knife) (S (VP (TO to) (VP (VB kill) (NP (DT the) (NNS chickens))))))) (. .)))