( I ( ( have ( ( learned ( from ( past experience ) ) ) ( that ( it ( ( is ( very ( difficult ( for students ) ) ) ) ( to ( ( catch up ) ( once ( they ( ( ( fall behind ) , ) ( for ( any reason ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP have) (VP (VBN learned) (PP (IN from) (NP (JJ past) (NN experience))) (SBAR (IN that) (S (NP (PRP it)) (VP (VBZ is) (ADJP (RB very) (JJ difficult) (PP (IN for) (NP (NNS students)))) (S (VP (TO to) (VP (VB catch) (PRT (RP up)) (SBAR (IN once) (S (NP (PRP they)) (VP (VBP fall) (ADVP (RB behind)) (, ,) (PP (IN for) (NP (DT any) (NN reason)))))))))))))) (. .)))
I have learned from past experience that it is very difficult for students to catch up once they fall behind, for any reason.
(ROOT (S (NP (NNP Insight) (NNP learning)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (S (VP (VBG learning) (PP (IN from) (NP (JJ past) (NNS experiences) (CC and) (NN reasoning)))))))) (. .)))