I have several phrases in my text such as

'The changes are consistent with post radiotherapy phrases'

I would like to pick these sentences up

Is there a way of using parts of speech to determine temporal prepositions specifically eg a tag pattern?

  • At least one example you give ('previous EMR') isn't a preposition. Mar 23 '19 at 16:27
  • OK. Sorry. I've corrected it Mar 23 '19 at 16:44
  • 2
    In your example, "post" is not a preposition but a prefix, though it does of course have a temporal meaning. Thus the word should be hyphenated "post-radiotherapy".
    – BillJ
    Mar 28 '19 at 9:16

Short Answer: Part of speech tags can not be used to determine temporal prepositions.

Long Answer: If you really want to do this, extract the prepositional phrases, and run those phrases through 'prepositional sense disambiguation' system. They will use a combination of the preposition plus the object of the preposition to determine if the PP was indeed being used to indicate a temporal notion.

UPDATE: Also see the book, "Neural Networks for Natural Language Processing" by Yoav Goldberg. Chapter 7.6 walks the reader through the detailed steps of preposition sense disambiguation.

  • 1
    But .... "post" is not a preposition but a prefix, so "post-radiotherapy" is a single word, not a prep+noun syntactic construction.
    – BillJ
    Mar 28 '19 at 9:22
  • 1
    Lexicographers don't agree on this one. See 4th PoS, en.oxforddictionaries.com/definition/post IMHO, it sure works like a preposition, "The food will be ready post 5pm." (after). One might argue that 'post' is a prefix to '5pm', but it seems cleaner as a preposition. Mar 28 '19 at 22:46
  • It may work like one, but the fact is that it isn't one. It only has noun and verb forms. I would hyphenate post-5pm, just like its opposite "pre-5pm", where "pre" is clearly a prefix, not a prep. By contrast "after" occurs as a temporal preposition in compounds such as "afternoon" "after-care", "after-thought" and the like. Btw, I think the Oxford is wrong -- in the example it gives, "post" is used incorrectly.
    – BillJ
    Mar 29 '19 at 8:31
  • Oxford also recognizes 'pre' as a preposition. Of the 11,000 "event words" that semantically could use the 'post' prefix, dictionaries recognize only 100 - 700 as lexical items. Interesting to note, the dictionaries that don't recognize 'post' as a preposition, also don't recognize the hyphenated entry, leaving us with 10,000+ neologisms. Mar 29 '19 at 14:11
  • 1
    I agree - liberties can be taken with hyphens (pre-1701, pre-1702, pre-1703, ...) If 'pre' and 'post' can be attached to any number, and those constructions represent a compound word, than there would be an infinite number of compound words. By treating the prefix as a preposition, you avoid the 'infinite compound word' dilemma. Great quote: "Hyphenation in English is subject to fashion and arbitrary prescription, some of which may appear to give differences between national varieties." Mar 29 '19 at 15:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.