fasttag part of speech tagger implementation

Usage no npm install needed!

<script type="module">
  import partsOfSpeech from '';



pos-js is a Javascript port of Mark Watson's FastTag Part of Speech Tagger which was itself based on Eric Brill's trained rule set and English lexicon.

pos-js also includes a basic lexer that can be used to extract words and other tokens from text strings.

pos-js was written by Percy Wegmann and is available on Google code. This fork adds node.js and npm support.


jspos is licensed under the GNU LGPLv3


$ npm install pos


var pos = require('pos');
var words = new pos.Lexer().lex('This is some sample text. This text can contain multiple sentences.');
var tagger = new pos.Tagger();
var taggedWords = tagger.tag(words);
for (i in taggedWords) {
    var taggedWord = taggedWords[i];
    var word = taggedWord[0];
    var tag = taggedWord[1];
    console.log(word + " /" + tag);

// extend the lexicon
tagger.extendLexicon({'Obama': ['NNP']});
tagger.tag(['Mr', 'Obama']);
// --> [[ 'Mr', 'NNP' ], [ 'Obama', 'NNP' ]]


Thanks to Mark Watson for writing FastTag, which served as the basis for jspos.


CC Coord Conjuncn           and,but,or
CD Cardinal number          one,two
DT Determiner               the,some
EX Existential there        there
FW Foreign Word             mon dieu
IN Preposition              of,in,by
JJ Adjective                big
JJR Adj., comparative       bigger
JJS Adj., superlative       biggest
LS List item marker         1,One
MD Modal                    can,should
NN Noun, sing. or mass      dog
NNP Proper noun, sing.      Edinburgh
NNPS Proper noun, plural    Smiths
NNS Noun, plural            dogs
POS Possessive ending       �s
PDT Predeterminer           all, both
PP$ Possessive pronoun      my,one�s
PRP Personal pronoun         I,you,she
RB Adverb                   quickly
RBR Adverb, comparative     faster
RBS Adverb, superlative     fastest
RP Particle                 up,off
SYM Symbol                  +,%,&
TO �to�                     to
UH Interjection             oh, oops
VB verb, base form          eat
VBD verb, past tense        ate
VBG verb, gerund            eating
VBN verb, past part         eaten
VBP Verb, present           eat
VBZ Verb, present           eats
WDT Wh-determiner           which,that
WP Wh pronoun               who,what
WP$ Possessive-Wh           whose
WRB Wh-adverb               how,where
, Comma                     ,
. Sent-final punct          . ! ?
: Mid-sent punct.           : ; �
$ Dollar sign               $
# Pound sign                #
" quote                     "
( Left paren                (
) Right paren               )