(S (S (ADVP (RB However)) (COMMA ,) (S (PP (IN on) (NP (BASENP (NNP February) (NN 1)) (COMMA ,) (BASENP (NN 2006)))) (COMMA ,) (S (BASENP (NNP Yeltsin)) (VP (VBD celebrated) (BASENP (PRPD his) (JJ 75th) (NN birthday)))))) (PERIOD .))