$re = '/\b(?:[^\W_]+_[^\W_]+ )?(?<!_PN |_PN1 |_PNQ[OVS] |_PNX1 |_PPGE |_PPH1 |_PPHO[12] |_PPHS2 |_PPIO[12] |_PPIS[12] |_PPX[12] |_PPY )[^\W_]*_V\w*/m';
$str = 'Ya_UH and_CC then_RT uhm_NN1 we_PPIS2 wrote_VVD in_RP but_CCB already_RR taken_VVN up_RP that_DD1 day_NNT1 that_CST we_PPIS2 wanted_VVD actually_RR they_PPHS2 said_VVD still_RR available_JJ you_PPY know_VV0 so_RR by_II that_DD1 time_NNT1 we_PPIS2 we_PPIS2 write_VV0 in_II our_APPGE letter_NN1 two_MC weeks_NNT2 later_RRR already_RR taken_VVN up_RP Quite_RG good_RR uh_UH P ICE-SIN:S1A-001#74:1:B Ask_VV0 her_PPHO1 I_PPIS1 left_VVD my_APPGE house_NN1 at_II one_MC1 met_VVD PRO_NN1 in_II school_NN1 at_II two_MC Ya_PPY so_RR waited_VVD you_PPY know_VV0 they_PPHS2 say_VV0 half_DB hour_NNT1 later_RRR And_CC and_CC it_PPH1 was_VBDZ still_RR drizzling_JJ and_CC raining_VVG
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php