( They ( ( confirm ( that ( you ( appreciated ( another ( 's ( work ( , ( gift ( , ( or thoughtfulness ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP confirm) (SBAR (IN that) (S (NP (PRP you)) (VP (VBD appreciated) (SBAR (S (NP (DT another)) (VP (VBZ 's) (NP (NN work) (, ,) (NN gift) (, ,) (CC or) (NN thoughtfulness))))))))) (. .)))
They confirm that you appreciated another's work, gift, or thoughtfulness.
(ROOT (S (S (VP (TO To) (VP (VB confirm) (NP (NP (DT the) (NN work)) (PP (IN of) (NP (DT another) (NN scientist))))))) (, ,) (NP (DT a) (NN scientist)) (VP (MD might) (VP (VB replicate) (NP (PRP$ their) (NN work)))) (. .)))