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> To understand the importance of PFS, consider these two sentences: "A dog bit my friend" and "My friend bit a dog." It is impossible to distinguish the differ

> To understand the importance of PFS, consider these two sentences: "A dog bit my friend" and "My friend bit a dog." It is impossible to distinguish the difference in meaning using words or grammar alone, since both words and grammatical structure are identical in these two sentences. Am I missing something here? Those two sentences are absolutely distinguishable grammatically - in one of the them the subject is "a dog" and the object is "my friend" and in the other the subject is "my friend" and the object is "a dog". I realize this is kind of nitpick, but at the very least this is a very bad example to use to demonstrate the importance of this PFS concept.

chowells 7y ago
You're confusing semantics with grammar. They have identical grammar. "(A dog) bit (my friend)." "(My friend) bit (a dog)." Both parse as "(compound subject) verb (compound object)." Both "my" and "a" function as adjectives modifying the single noun after them. The sentences have identical parse trees, even when considering the types of the nodes. They are grammatically identical.
- riffraff 7y ago
  Are they though? Isn't 'a' an indeterminate article and 'my' a pronoun? I get the point of the example, but it seems different at the grammatical level too. Subject/object should be at a different level above grammar.
  - mannykannot 7y ago
    Substitute 'my' for the 'a's?
    - kazinator 7y ago
      You can't be randomly substituting words for other words (let alone ones with different lexical categories) and keep claiming that you have the same parse tree!
      - mannykannot 7y ago
        Agreed, and of course the meaning also changes - What I mean is that you can have a different example that makes the point while avoiding this particular issue.
  - Smithalicious 7y ago
    "A dog bit a friend" and "my dog bit my friend" still work the same, though.
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    - riffraff 7y ago
      Indeed, I think it's just an incorrect example, the point gets across anyway.
  - jerf 7y ago
    It may be easier to understand the point being made here if we consider what it means to be entirely absent these grammar. AIUI, but can't come up with a concrete link on the Internet quickly, Koko, the gorilla that knew some ASL, tended to speak in sentences like "Koko koko cup cup cup koko koko want want want cup cup cup", if they were transcribed literally. With such utterances, there is no way to distinguish between "Koko wants the cup" and "The cup wants Koko", or even "Koko wants the cup to want Koko". There are animals that have demonstrated some "semantics". There are parrots that do better than Koko with spoken language, but still do not produce anything like the grammatical constructs humans do. Everything I've seen out of parrots could be covered by memorizing a handful of grammar constructs in a very brute-force manner, and they have no deliberate ability to combine them. The core point is that to distinguish '"A dog bit my friend" and "My friend bit a dog."' requires grammar, which so far as I know as one who tends to pay attention to these things, is not a thing that animals have ever demonstrated a deep understanding of (if there are animals that could distinguish that, that is probably their maximum limit) and certainly never demonstrated production of. (Or, at the very least, we've never decoded and proved is speech, if you're thinking of whales and dolphins and such.) If you produce and understand speech as the Koko sentence above, you can't distinguish those two sentences. It's not about whether changing subject and object makes a "different sentence" by some metric, it's about whether the animal in question has a well-defined usage of subject and object as distinct grammatical categories at all. For example, in my sentence "The cup wants Koko" I used earlier, it is invalid, yet everyone here reading it has at the very least the same understanding of why it is invalid, because what it says and the grammar of why it says that is completely clear to us.
  - chowells 7y ago
    Others have addressed most of this, but no one else has called this out specifically: "my" is not a pronoun. Pronouns stand in for nouns. "my" stands in for a determiner. Both replace concrete with relative, but that's a semantic category that doesn't impact syntactic class.
  - _emacsomancer_ 7y ago
    Syntactically, they're both determiners. Semantically, they're a bit different since possessives (like 'my') aren't closed under permutation†, while many other determiners ('some', 'every', 'most' &c.) are closed under permutation. † An operation mapping a set X onto another X' by relating every member of X with some member of X', so that X' has the same number of members as X, but the identity of the members may be different.
- kazinator 7y ago
  Nope; these sentences share a common root-level grammar production, that's all. They are not identical. They are similar at this production step: S -> subj verb obj The verb is common: verb -> ... -> bit So we have the same overall sentence pattern with the same verb, in the same tense. Other than that, the derivation diverges: subj -> ... -> a dog subj -> ... -> my friend You can't just ignore substructure differences and symbol identities in comparing trees! Of course, any two things are the same, if you choose to ignore anything that is different and define "sameness" that way.
  - chowells 7y ago
    Ignoring the symbols is exactly what is meant by "the grammar" of a sentence. Two things are grammatically the same if they use the same grammar productions when parsing/producing. This isn't conveniently bending definitions to make myself sound correct. This is the specific technical definition that was worked out by linguists in their empirical examination of language (and later adopted by computer scientists because it happens to work nicely with programming languages too). It might not match with some colloquial uses, but it's a reasonable assumption that an article discussing linguistics would be using the precise linguistic definition.
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trixie_ 7y ago
It's a great example. No rule will tell you why one is funny and the other is not.
chubot 7y ago
Yeah that was my first thought too. It's absolutely possible to distinguish the meaning between those two sentences using grammar alone. Grammars make sense of sequences of symbols, i.e. order matters. Only if you claim there is no difference between "dog" and "friend" can you claim that the two sentences are indistinguishable. But that's why they are different words -- so you can tell them apart :)
- danaliv 7y ago
  Order matters in English, because it lost its Germanic declensions. In highly inflected languages order is less relevant to meaning.
blevo 7y ago
to build/combine on two comments in the thread before mine: word position matters in English as you demonstrated. "A dog bit my friend" has different meaning than "My friend bit my dog". In other languages, differentiating between subject/object is done differently. example: "A doggo bit my friendee" or "My friendo bit a dogee" and you can see the difference. Word order is still somewhat relevant here because I didn't add endings to the verb too, which is commonplace in such languages. When you do that you are able to be far more free with word position: My Friendee doggo bitto. Bitto My friendee doggo. In this way it's easier to tell the subject/object difference.[1] To some degree this can be done in English and is exactly what Yoda does: "My friend a dog bit" but that sentence can be either of the ones you gave. Adding a comma may help "My friend, a dog bit" = "A dog bit my friend" [1] This is exactly what Latin does and as rjf72 mentioned it gives more freedom. Many Latin authors put the verb at the end which gives you a sort of suspense as to just what is happening. In my second example I put the verb up front and the subject at the end which allows me to keep you in suspense as to who did the biting.
buboard 7y ago
Syntactically. Not grammatically. The author put it wrong
Vrondi 7y ago
No, they are grammatically identical, with a subject performing action on an object. The only difference is that the subject and object are interchanged.

chowells 7y ago

You're confusing semantics with grammar. They have identical grammar. "(A dog) bit (my friend)." "(My friend) bit (a dog)." Both parse as "(compound subject) verb (compound object)." Both "my" and "a" function as adjectives modifying the single noun after them. The sentences have identical parse trees, even when considering the types of the nodes. They are grammatically identical.

riffraff 7y ago
Are they though? Isn't 'a' an indeterminate article and 'my' a pronoun? I get the point of the example, but it seems different at the grammatical level too. Subject/object should be at a different level above grammar.
- mannykannot 7y ago
  Substitute 'my' for the 'a's?
  - kazinator 7y ago
    You can't be randomly substituting words for other words (let alone ones with different lexical categories) and keep claiming that you have the same parse tree!
    - mannykannot 7y ago
      Agreed, and of course the meaning also changes - What I mean is that you can have a different example that makes the point while avoiding this particular issue.
- Smithalicious 7y ago
  "A dog bit a friend" and "my dog bit my friend" still work the same, though.
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  - riffraff 7y ago
    Indeed, I think it's just an incorrect example, the point gets across anyway.
- jerf 7y ago
  It may be easier to understand the point being made here if we consider what it means to be entirely absent these grammar. AIUI, but can't come up with a concrete link on the Internet quickly, Koko, the gorilla that knew some ASL, tended to speak in sentences like "Koko koko cup cup cup koko koko want want want cup cup cup", if they were transcribed literally. With such utterances, there is no way to distinguish between "Koko wants the cup" and "The cup wants Koko", or even "Koko wants the cup to want Koko". There are animals that have demonstrated some "semantics". There are parrots that do better than Koko with spoken language, but still do not produce anything like the grammatical constructs humans do. Everything I've seen out of parrots could be covered by memorizing a handful of grammar constructs in a very brute-force manner, and they have no deliberate ability to combine them. The core point is that to distinguish '"A dog bit my friend" and "My friend bit a dog."' requires grammar, which so far as I know as one who tends to pay attention to these things, is not a thing that animals have ever demonstrated a deep understanding of (if there are animals that could distinguish that, that is probably their maximum limit) and certainly never demonstrated production of. (Or, at the very least, we've never decoded and proved is speech, if you're thinking of whales and dolphins and such.) If you produce and understand speech as the Koko sentence above, you can't distinguish those two sentences. It's not about whether changing subject and object makes a "different sentence" by some metric, it's about whether the animal in question has a well-defined usage of subject and object as distinct grammatical categories at all. For example, in my sentence "The cup wants Koko" I used earlier, it is invalid, yet everyone here reading it has at the very least the same understanding of why it is invalid, because what it says and the grammar of why it says that is completely clear to us.
- chowells 7y ago
  Others have addressed most of this, but no one else has called this out specifically: "my" is not a pronoun. Pronouns stand in for nouns. "my" stands in for a determiner. Both replace concrete with relative, but that's a semantic category that doesn't impact syntactic class.
- _emacsomancer_ 7y ago
  Syntactically, they're both determiners. Semantically, they're a bit different since possessives (like 'my') aren't closed under permutation†, while many other determiners ('some', 'every', 'most' &c.) are closed under permutation. † An operation mapping a set X onto another X' by relating every member of X with some member of X', so that X' has the same number of members as X, but the identity of the members may be different.
kazinator 7y ago
Nope; these sentences share a common root-level grammar production, that's all. They are not identical. They are similar at this production step: S -> subj verb obj The verb is common: verb -> ... -> bit So we have the same overall sentence pattern with the same verb, in the same tense. Other than that, the derivation diverges: subj -> ... -> a dog subj -> ... -> my friend You can't just ignore substructure differences and symbol identities in comparing trees! Of course, any two things are the same, if you choose to ignore anything that is different and define "sameness" that way.
- chowells 7y ago
  Ignoring the symbols is exactly what is meant by "the grammar" of a sentence. Two things are grammatically the same if they use the same grammar productions when parsing/producing. This isn't conveniently bending definitions to make myself sound correct. This is the specific technical definition that was worked out by linguists in their empirical examination of language (and later adopted by computer scientists because it happens to work nicely with programming languages too). It might not match with some colloquial uses, but it's a reasonable assumption that an article discussing linguistics would be using the precise linguistic definition.
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deleted 7y ago

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trixie_ 7y ago

It's a great example. No rule will tell you why one is funny and the other is not.

chubot 7y ago

Yeah that was my first thought too. It's absolutely possible to distinguish the meaning between those two sentences using grammar alone. Grammars make sense of sequences of symbols, i.e. order matters. Only if you claim there is no difference between "dog" and "friend" can you claim that the two sentences are indistinguishable. But that's why they are different words -- so you can tell them apart :)

danaliv 7y ago
Order matters in English, because it lost its Germanic declensions. In highly inflected languages order is less relevant to meaning.

blevo 7y ago

to build/combine on two comments in the thread before mine: word position matters in English as you demonstrated. "A dog bit my friend" has different meaning than "My friend bit my dog". In other languages, differentiating between subject/object is done differently. example: "A doggo bit my friendee" or "My friendo bit a dogee" and you can see the difference. Word order is still somewhat relevant here because I didn't add endings to the verb too, which is commonplace in such languages. When you do that you are able to be far more free with word position: My Friendee doggo bitto. Bitto My friendee doggo. In this way it's easier to tell the subject/object difference.[1] To some degree this can be done in English and is exactly what Yoda does: "My friend a dog bit" but that sentence can be either of the ones you gave. Adding a comma may help "My friend, a dog bit" = "A dog bit my friend" [1] This is exactly what Latin does and as rjf72 mentioned it gives more freedom. Many Latin authors put the verb at the end which gives you a sort of suspense as to just what is happening. In my second example I put the verb up front and the subject at the end which allows me to keep you in suspense as to who did the biting.

buboard 7y ago

Syntactically. Not grammatically. The author put it wrong

Vrondi 7y ago

No, they are grammatically identical, with a subject performing action on an object. The only difference is that the subject and object are interchanged.