Bottom-up  the young being inducted into school at an early age and proceeding, level by level, to institutions of ever  higher  learning, stopping off for various reasons at various levels, usually marked by tests and the distribution of certificates providing a social grade.
( ( ( Bottom-up ( the young ) ) ( ( ( being ( ( inducted ( into school ) ) ( at ( an ( early age ) ) ) ) ) and ) proceeding ) ) ( , ( ( ( ( ( level ( by level ) ) , ) ( to ( institutions ( of ( ( ( ( ever higher ) learning ) , ) ( ( ( stopping off ) ( for ( various reasons ) ) ) ( at ( various levels ) ) ) ) ) ) ) ) , ) ( usually ( ( ( marked ( by ( ( tests and ) ( ( the distribution ) ( of certificates ) ) ) ) ) ( providing ( a ( social grade ) ) ) ) . ) ) ) ) )
(ROOT (S (S (VP (VBG Bottom-up) (NP (DT the) (JJ young)) (S (VP (VP (VBG being) (VP (VBN inducted) (PP (IN into) (NP (NN school))) (PP (IN at) (NP (DT an) (JJ early) (NN age))))) (CC and) (VP (VBG proceeding)))))) (, ,) (NP (NP (NN level)) (PP (IN by) (NP (NN level))) (, ,) (PP (TO to) (NP (NP (NNS institutions)) (PP (IN of) (S (VP (VP (ADVP (RB ever) (JJR higher)) (VBG learning)) (, ,) (VP (VBG stopping) (PRT (RP off)) (PP (IN for) (NP (JJ various) (NNS reasons))) (PP (IN at) (NP (JJ various) (NNS levels))))))))) (, ,)) (ADVP (RB usually)) (VP (VBD marked) (PP (IN by) (NP (NP (NNS tests)) (CC and) (NP (NP (DT the) (NN distribution)) (PP (IN of) (NP (NNS certificates)))))) (S (VP (VBG providing) (NP (DT a) (JJ social) (NN grade))))) (. .)))
Young people enter the school system and go level by level through different instutions.
( ( Young people ) ( ( ( ( enter ( the ( school system ) ) ) and ) ( ( ( go level ) ( by level ) ) ( through ( different instutions ) ) ) ) . ) )
(ROOT (S (NP (NNP Young) (NNS people)) (VP (VP (VB enter) (NP (DT the) (NN school) (NN system))) (CC and) (VP (VB go) (NP (NN level)) (PP (IN by) (NP (NN level))) (PP (IN through) (NP (JJ different) (NNS instutions))))) (. .)))