Attachment ambiguity of the day

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Prepositional phrase attachment is one of the hardest things for English parsers to get right: if I hit a man with a bag of groceries, was that bag of groceries the instrument of my action, or was it just something the guy was carrying when I attacked him?

And PP-attachment ambiguity is especially common in English-language headlines, since omitted forms of to be add additional ambiguous attachment points.

For example, Alex Barker, "EU reforms to break up big banks at risk", Financial Times 1/29/2015: Are the reforms at risk, or are the reforms on track to break up banks that are at risk?

And it might not have occurred to you that there's a third option, where "at risk" modifies the verb break up, as if the phrase were something like "EU reforms to break up big banks on Monday".

Both the Berkeley and the Stanford parsers choose that third option. And in addition, the Berkeley parser thinks that "reforms" is a verb rather than a noun:

The article's text makes it clear that it's the reforms rather than the banks that are at risk:

Reforms to break up Europe’s big banks are on course to be weakened by pressure from France and Britain for maximum national leeway.

The European Commission has faced a wall of opposition from some EU member states and the banking industry since it made proposals last year to force some banks to hive off risky trading activities.

Resistance is coalescing around options to defang the regulation. Officials from five of the most sceptical countries — France, the UK, Germany, Sweden and the Netherlands — meet in Riga on Friday to discuss potential compromises.

 Of course, that would be the politically more plausible bet,  regardless of whether low or high attachment is structurally or lexically more probable in this case

The obligatory screenshot:

[h/t Lane Greene]



  1. Irina said,

    January 30, 2015 @ 4:26 pm

    "I saw the man in the park with the telescope." Did I have the telescope, or the man, or the park?

  2. Andrew said,

    January 30, 2015 @ 4:57 pm

    "Last night I shot an elephant in my pyjamas. How it got into my pyjamas I'll never …"

    I'll get me coat.

  3. the other Mark P said,

    January 30, 2015 @ 5:02 pm

    The Berkeley parser then is reading it as:

    [The] EU reforms [itself in order] to break up big banks at risk

    Isn't that a fourth possible reading?

  4. davep said,

    January 30, 2015 @ 7:17 pm

    Goes to show that structure isn't enough to get the correct meaning.

    The problem with "I hit a man with a bag of groceries" is that it maps to a common sentence structure: "I hit X with a Y" where Y is the object used to hit (examples: "I hit a ball with a bat", "I hit a tree with a car"). Since a bag of groceries is an unlikely weapon, the "standard" interpretation doesn't seem likely to be correct.

    Since "I hit a man with a bag of groceries" is ambiguous, I'd say it's poorly written (and that not many people would write that sentence). Using familiar words and the same number of words: "I hit a man carrying a bag of groceries" or "I hit a man using a bag of groceries" (which isn't perfect either). Or "I hit a man with my bag of groceries". (If the person was stealing the the groceries, it would more likely be "I hit the man stealing my groceries".)

    Headlines are a problem.

  5. davep said,

    January 30, 2015 @ 7:25 pm

    To be a bit more brief, it's not likely that anybody would have to deal with the "groceries" sentence.

    Dealing with the second relates to "reforming big banks" being new ("news") and "big banks" (per se) not being new. And "at risk" being associated with what is "news" (namely, "reforming big banks").

  6. Daniel Barkalow said,

    January 30, 2015 @ 7:36 pm

    The Stanford parser has me imagining a couple of national central bankers in Europe, and they notice risk, and one of them says "We're putting the EU back together" and the other one (Elwood) says, "We're going to break up banks."

  7. GH said,

    January 30, 2015 @ 7:58 pm

    I'm wondering whether to read "at risk" as a location ("at the office") or a time ("at daybreak"), or some other interpretation where it binds to the verb. I find it very hard to make any semantic sense of in any case.

  8. davep said,

    January 30, 2015 @ 8:03 pm

    "At risk" is a common/familiar English phrase (and if you know what "risk" is, you know it's not a location).

  9. GH said,

    January 30, 2015 @ 8:38 pm

    Of course. I'm speaking in the context of the parsers' interpretations:

    "at risk" modifies the verb break up, as if the phrase were something like "EU reforms to break up big banks on Monday".

    I suppose in this reading you might interpret it as a telescoped form of "at its own risk," but I find that barely grammatical.

  10. Mark Meckes said,

    January 30, 2015 @ 10:00 pm

    My first reading of the headline was actually exactly what the other Mark P suggested.

    As for hitting a man with a bag of groceries, my intuition is that, spoken aloud by a native speaker, another native speaker would generally interpret it correctly. I agree with davep that, on the page, it's badly written.

  11. Oskar said,

    January 31, 2015 @ 1:49 am


    Using familiar words and the same number of words: "I hit a man carrying a bag of groceries" or "I hit a man using a bag of groceries" (which isn't perfect either).

    While reformulating it like that would remove ambiguity for humans, I would think that both of those sentences would be just as confusing for a computer to parse. "I hit a man carrying a bag of groceries" could well be interpreted as "While I was carrying a bag of groceries, I hit a man". Making the a small substitution and saying "I ran a marathon carrying a bag of groceries", that interpretation becomes the right one.

    The other one could be misinterpreted as well, seeing it as "I hit a man while he was using a bag of groceries". Now, we are clever humans who all know that you can't really "use" a bag of groceries, so that parsing becomes nonsensical. But if the sentence was "I hit a man using a cellphone", suddenly it's the right interpretation, given that cellphones make poor weapons.

    I guess the point is that in order to interpret any kind of attachment like this (regardless of whether it uses a preposition or a verb) requires an incredibly deep understanding of semantics and context, not just syntax. Unless you write them extremely carefully, sentences like these will always be ambiguous.

  12. Adam Roberts said,

    January 31, 2015 @ 6:35 am

    This raises the (to me) interesting question of probability in everyday interpretive semantics. I mean: in use, an interlocutor who hears 'I hit a man with a bag of groceries' is surely going to (a) recognise the ambiguity, then (b) work out which of the two possible means is more likely to be the one intended by the speaker. In this case, it seems to me that 'I hit [a man with a bag of groceries]' introduces a note of irrelevance — it seems unlikely that the fact that the man was carrying groceries is going to be relevant to my hitting him (Compare, let's say, 'I hit a man carrying a racist sign', or 'I hit a man carrying my wallet away'). On the other, the fact that people don't often hit others with bags of groceries makes 'I hit [a man] with a bag of groceries' more likely.

    My point is less to do with this specific statement, and more about linguistics in general. In 'probability' (in this sense) an accepted part of linguistic analysis?

  13. DaveK said,

    January 31, 2015 @ 7:18 pm

    There was a wonderfully snarled mess of prepositional phrases in a photo caption on Slate today:

    "Lebanese Hezbollah militants pray at the grave of Hezbollah commander Imad Mughniyah (portrait), who was killed in a car bombing in Damascus in 2008, during a ceremony commemorating the 3rd anniversary of his assassination on Feb. 13, 2011."

    I had to read this carefully before I was sure he hadn't been killed twice.

  14. GH said,

    February 1, 2015 @ 7:16 am

    @Adam Roberts:

    I had the same thought (contra other commenters who seem to prefer the interpretation where the man was carrying the bag), and associated it with the Gricean cooperative principle of conversation, which I was fascinated to first hear about here on the Language Log.

  15. Mark S said,

    February 1, 2015 @ 9:46 am

    Regarding probability: I might have thought that a more probable event would be the more likely meaning of the sentence; but it seems that there's a Gricean effect that a more likely event is less likely to be worth saying, and so less likely to be the correct meaning.

  16. rwmg said,

    February 2, 2015 @ 11:58 pm

    I have hit a man with a bag of groceries. I was on the way home from shopping and he tried to pick my pocket. It seemed the best thing to do at the time as my hands were full.

  17. January First-of-May said,

    February 3, 2015 @ 12:32 am

    IMHO, as far as bags of groceries go, it's a lot more likely for one to be used as a hitting implement than be held by a person being hit.
    And if "bump accidentally in the subway" counts as "hit", the probability is in favor of the hitting implement by orders of magnitude (as such bags tend to stick out).

    On the headline meaning, my first impression was the same as that of Mark Meckes (and the other Mark P) – I interpreted "reforms" as a verb, as in "EU reforms itself to" (I also thought it's the big banks that are at risk).

  18. chris said,

    February 4, 2015 @ 11:00 pm

    if I hit a man with a bag of groceries

    Did this remind anyone else of the "You wouldn't hit a man with glasses" bit from _Wreck-It Ralph_?

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