# CHILDES Treebank labels taken from Penn Treebank II Tags

Note: This information comes from "Bracketing Guidelines for Treebank II Style Penn Treebank Project" - part of the documentation that comes with the Penn Treebank.

## Contents:

- Bracket Labels
  - Clause Level
  - Phrase Level
  - Word Level

  ## Bracket Labels

  ### Clause Level

  S - simple declarative clause, i.e. one that is not introduced by a (possible empty) subordinating conjunction or a wh-word and that does not exhibit subject-verb inversion.
  SBAR - Clause introduced by a (possibly empty) subordinating conjunction.
  SBARQ - Direct question introduced by a wh-word or a wh-phrase. Indirect questions and relative clauses should be bracketed as SBAR, not SBARQ.
  SINV - Inverted declarative sentence, i.e. one in which the subject follows the tensed verb or modal.
  SQ - Inverted yes/no question, or main clause of a wh-question, following the wh-phrase in SBARQ.

  ### Phrase Level

  ADJP - Adjective Phrase.
  ADVP - Adverb Phrase.
  CONJP - Conjunction Phrase. **NOTE: Not used in CHILDES Treebank.
  FRAG - Fragment.
  INTJ - Interjection. Corresponds approximately to the part-of-speech tag UH.
  LST - List marker. Includes surrounding punctuation. **NOTE: Not used in CHILDES Treebank.
  NAC - Not a Constituent; used to show the scope of certain prenominal modifiers within an NP. **NOTE: Not used in CHILDES Treebank.
  NP - Noun Phrase.
  NX - Used within certain complex NPs to mark the head of the NP. Corresponds very roughly to N-bar level but used quite differently. **NOTE: Not used in CHILDES Treebank.
  PP - Prepositional Phrase.
  PRN - Parenthetical. **NOTE: Not used in CHILDES Treebank.
  PRT - Particle. Category for words that should be tagged RP.
  QP - Quantifier Phrase (i.e. complex measure/amount phrase); used within NP. **NOTE: Not used in CHILDES Treebank.
  RRC - Reduced Relative Clause. **NOTE: Not used in CHILDES Treebank.
  UCP - Unlike Coordinated Phrase. **NOTE: Not used in CHILDES Treebank.
  VP - Verb Phrase.
  WHADJP - Wh-adjective Phrase. Adjectival phrase containing a wh-adverb, as in how hot.
  WHADVP - Wh-adverb Phrase. Introduces a clause with an NP gap. May be null (containing the 0 complementizer) or lexical, containing a wh-adverb such as how or why.
  WHNP - Wh-noun Phrase. Introduces a clause with an NP gap. May be null (containing the 0 complementizer) or lexical, containing some wh-word, e.g. who, which book, whose daughter, none of which, or how many leopards.
  WHPP - Wh-prepositional Phrase. Prepositional phrase containing a wh-noun phrase (such as of which or by whose authority) that either introduces a PP gap or is contained by a WHNP.
  X - Unknown, uncertain, or unbracketable. X is often used for bracketing typos and in bracketing the...the-constructions. **NOTE: Not used in CHILDES Treebank.

  ### Word level

  CC - Coordinating conjunction
  CD - Cardinal number
  DT - Determiner
  EX - Existential there
  FW - Foreign word
  IN - Preposition or subordinating conjunction
  JJ - Adjective
  JJR - Adjective, comparative
  JJS - Adjective, superlative
  LS - List item marker. **NOTE: Not used in CHILDES Treebank
  MD - Modal
  NN - Noun, singular or mass
  NNS - Noun, plural
  NNP - Proper noun, singular
  NNPS - Proper noun, plural
  PDT - Predeterminer
  POS - Possessive ending
  PRP - Personal pronoun
  PRP$ - Possessive pronoun (prolog version PRP-S)
  RB - Adverb
  RBR - Adverb, comparative
  RBS - Adverb, superlative
  RP - Particle
  SYM - Symbol. **NOTE: Not used in CHILDES Treebank.
  TO - to
  UH - Interjection
  VB - Verb, base form
  VBD - Verb, past tense
  VBG - Verb, gerund or present participle
  VBN - Verb, past participle
  VBP - Verb, non-3rd person singular present
  VBZ - Verb, 3rd person singular present
  WDT - Wh-determiner
  WP - Wh-pronoun
  WP$ - Possessive wh-pronoun (prolog version WP-S)
  WRB - Wh-adverb