Penn Treebank II Constituent 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
• Function Tags
  • Form/function discrepancies
  • Grammatical role
  • Adverbials
  • Miscellaneous
• Index of All Tags

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

Adverbials are generally VP adjuncts.

-BNF (benefactive) - marks the beneficiary of an action (attaches to NP or PP).
This tag is used only when (1) the verb can undergo dative shift and (2) the prepositional variant (with the same meaning) uses for. The prepositional objects of dative-shifting verbs with other prepositions than for (such as to or of) are annotated -DTV.
-DIR (direction) - marks adverbials that answer the questions "from where?" and "to where?" It implies motion, which can be metaphorical as in "...rose 5 pts. to 57-1/2" or "increased 70% to 5.8 billion yen" -DIR is most often used with verbs of motion/transit and financial verbs.
-EXT (extent) - marks adverbial phrases that describe the spatial extent of an activity. -EXT was incorporated primarily for cases of movement in financial space, but is also used in analogous situations elsewhere. Obligatory complements do not receive -EXT. Words such as fully and completely are absolutes and do not receive -EXT.
-LOC (locative) - marks adverbials that indicate place/setting of the event. -LOC may also indicate metaphorical location. There is likely to be some varation in the use of -LOC due to differing annotator interpretations. In cases where the annotator is faced with a choice between -LOC or -TMP, the default is -LOC. In cases involving SBAR, SBAR should not receive -LOC. -LOC has some uses that are not adverbial, such as with place names that are adjoined to other NPs and NAC-LOC premodifiers of NPs. The special tag -PUT is used for the locative argument of put.
-MNR (manner) - marks adverbials that indicate manner, including instrument phrases.
-PRP (purpose or reason) - marks purpose or reason clauses and PPs.
-TMP (temporal) - marks temporal or aspectual adverbials that answer the questions when, how often, or how long. It has some uses that are not strictly adverbial, auch as with dates that modify other NPs at S- or VP-level. In cases of apposition involving SBAR, the SBAR should not be labeled -TMP. Only in "financialspeak," and only when the dominating PP is a PP-DIR, may temporal modifiers be put at PP object level. Note that -TMP is not used in possessive phrases.

Miscellaneous

• on S or SBAR - These categories are usually arguments, so the -CLR tag indicates that the clause is more adverbial than normal clausal arguments. The most common case is the infinitival semi-complement of use, but there are a variety of other cases.
• on PP, ADVP, SBAR-PRP, etc - On categories that are ordinarily interpreted as (adjunct) adverbials, -CLR indicates a somewhat closer relationship to the verb. For example:
  • Prepositional Ditransitives
    In order to ensure consistency, the Treebank recognizes only a limited class of verbs that take more than one complement (-DTV and -PUT and Small Clauses) Verbs that fall outside these classes (including most of the prepositional ditransitive verbs in class [D2]) are often associated with -CLR.
  • Phrasal verbs
    Phrasal verbs are also annotated with -CLR or a combination of -PRT and PP-CLR. Words that are considered borderline between particle and adverb are often bracketed with ADVP-CLR.
  • Predication Adjuncts
    Many of Quirk's predication adjuncts are annotated with -CLR.
• on NP - To the extent that -CLR is used on NPs, it indicates that the NP is part of some kind of "fixed phrase" or expression, such as take care of. Variation is more likely for NPs than for other uses of -CLR.