It is difficult for the nonspecialist reader (like me) to assess the validity of his arguments, which are based on his contention that the language (and its congeners) were carried along by the spread of nomad pastoralism.
( It ( ( ( ( is ( difficult ( for ( ( the ( nonspecialist reader ) ) ( -LRB- ( ( like me ) -RRB- ) ) ) ) ) ) ( to ( assess ( ( the validity ) ( of ( ( ( his arguments ) , ) ( which ( are ( based ( on ( his contention ) ) ) ) ) ) ) ) ) ) ) ( that ( ( ( ( ( ( the language ) -LRB- ) and ) ( its congeners ) ) -RRB- ) ( were ( ( carried along ) ( by ( ( the spread ) ( of ( nomad pastoralism ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (ADJP (JJ difficult) (PP (IN for) (NP (NP (DT the) (JJ nonspecialist) (NN reader)) (PRN (-LRB- -LRB-) (PP (IN like) (NP (PRP me))) (-RRB- -RRB-))))) (S (VP (TO to) (VP (VB assess) (NP (NP (DT the) (NN validity)) (PP (IN of) (NP (NP (PRP$ his) (NNS arguments)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBP are) (VP (VBN based) (PP (IN on) (NP (PRP$ his) (NN contention))))))))))))) (SBAR (IN that) (S (NP (NP (DT the) (NN language)) (-LRB- -LRB-) (CC and) (NP (PRP$ its) (NNS congeners)) (-RRB- -RRB-)) (VP (VBD were) (VP (VBN carried) (PRT (RP along)) (PP (IN by) (NP (NP (DT the) (NN spread)) (PP (IN of) (NP (JJ nomad) (NN pastoralism)))))))))) (. .)))
It's clear to me that his arguments make no sense.
( It ( ( ( 's ( clear ( to me ) ) ) ( that ( ( his arguments ) ( make ( no sense ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ 's) (ADJP (JJ clear) (PP (TO to) (NP (PRP me)))) (SBAR (IN that) (S (NP (PRP$ his) (NNS arguments)) (VP (VBP make) (NP (DT no) (NN sense)))))) (. .)))