Syntax 1 Wiki: Week 5: Difference between revisions

From English Grammar
Jump to navigation Jump to search
 
(71 intermediate revisions by 2 users not shown)
Line 1: Line 1:
<font face="Arial, Helvetica, sans-serif">
<font size="3">
<font face="Arial, Helvetica, sans-serif">
<font face="Arial, Helvetica, sans-serif">
<font size="3">
<font size="3">


== Introduction ==
== Tracking the stucture-building process in detail ==


In the first weeks of this course, we have dealt with the topics:  
This week we are going study every detail of the licensing of phrases. For this purpose, we are going to study the interaction of the following concepts:


a. Parts of speech and their features<br>
# Word definitions
b. Predicate-argument Structure<br>
# Phrase definitions (again)
<!--
# Unification (= the merging of feature structures)
c. Feature structures. <br>
# The Head-Feature Principle
-->
This week, we are going to bring these topics together. Remember what the purpose of feature structures like the one below is:


[[File:book-Webelhuth.jpg]]
== Types ==


Feature structures describe an object (represented by the feature structure type in the top-left) by describing the values of the features that are relevant for that object. Thus, for a book we find such features as TITLE and AUTHOR, but not PHONE-NUMBER. The entries in a book catalogue will then presumably all be different, since they describe different books with different properties (= values for features), but the entries are all going to be structured similarly, since each entry describes a book with a feature structure of type ''book''.
Follow [[Syntax_1_Wiki:_Types|'''this link''']] to learn about the general properties of types.


Consider now the problem we face when we want to represent what speakers know about the words of their language. For simplicity's sake, we can assume that the speakers have something like a dictionary book in their heads, i.e. a long list of word entries. As in the book example above, the entry for each word will be different from the entries of all other words, but of course words have some features in common that we can capture in a feature structure type ''word''. For instance, every word will have a SYNTACTIC (SYN)<!--PHONOLOGY--> feature whose value specifies <!--the specific word's pronunciation--> the syntactic properties of the word. We are now beginning to define feature structure types for linguistic objects. Of course, as with every feature structure we will make sure that the features we postulate for a particular kind of linguistic object reflect the properties of that object!
[[File:Type-hierarchy.JPG|1000px|]]


Before we define the feature structure type ''word'', it is economical to first define the feature structure type ''sign''. The reason is that all words are signs and therefore words have all the properties of signs. Besides words (N, V, etc.), there is only one other specific type of sign, namely the syntactic phrase (NP, VP, etc.). <span style="color: blue>So, our strategy will be the following:</span>
== Unification ==


# <span style="color: blue>We define the most general feature structure type.</span>
We begin with the concept of '''unification.''' It simply means that you combine the information that you have about an object from two or more sources. Or, to put it differently, you combine two descriptions of the same object. Here is an example.
# <span style="color: blue>When there are objects that are specific versions of the general type, we define types for them, declare the more specific types as '''subtypes''' of the more general type.</span>
# <span style="color: blue>In the definitions of the subtypes we only specify those features and values that those types have in addition to their super type.</span>


== Feature structures of type ''sign'' ==
The easiest way to understand unification, is to see it in action.


So, in accordance with this procedure, we will define the type ''sign'' first. In preparation for this, we will look at a <span style="color: blue>feature structure of type ''sign''</span>:
'''Pickpocket Scenario 1'''


[[File:Sign_features.PNG]]
Imagine that Jill and Jack are at the Frankfurt Christmas market together. At some point, they see a pickpocket stealing somebody's purse. By the time they have alerted the police, the pickpocket has disappeared. The police officer asks them for a description of the pickpocket and gets the following answers:


Note that this feature structure is of the general format we specified for all feature structures:
Jill: the pickpocket


# In the top left we find the feature structure type: ''sign''.
* is a man
# Below the type, we find two rows of the form [FEATURE ''value'']:
* has blond hair
<!--* the feature PHON whose value is a feature structure of type ''list'' (of segments or letters)-->
* was wearing a jacket
* the feature <!--SYNSEM--> SYN whose value is a feature structure of type <!--''synsem''--> <b>cat</b> (category). The attributes of the feature structure of type <b><i>cat</i></b> are <b>POS</b> (part of speech), <b>SPR</b> (specifier), and <b>COMPS</b> (complements). The POS attribute(feature) has a corresponding value, which is a feature structure of type <b><i>pos</i></b>. The feature structure of type <b><i>pos</i></b> takes also features and values (i.e. the number and type of features depends on the category of the word we are describing). For example, if we are describing a word of category <b><i>v</i></b>(verb), the features(attributes) will be <b>VFORM</b> (verb form) and <b>AUX</b>(auxiliary). The value of the <b>VFORM</b> feature could be a finite or a non-finite (base, presp, perfp) forms. The value of the <b>AUX</b> feature can be either plus <b>+</b> or minus <b>-</b>. The <b>+</b> symbol would mean that the verb we are describing is a modal verb and the minus -- that the verb is not modal. The <b>SPR</b> attribute has a value, which is a list of possible specifiers and the <b>COMPS</b> attribute has a value, which is a list of possible complements.
** the jacket was black


Since lists and complexes of syntactic<!---semantic--> properties have internal structure (i.e. consist of parts), we describe these objects again in terms of feature structure types that are appropriate for a description of these objects. <!--As it happens, a feature structure of type ''synsem'' contains only one attribute, namely LOC(AL), with corresponding value ''loc''. -->
Jack: the pickpocket


It is easy to feel overwhelmed by the representation above at first, but don't worry! You will see so many concrete examples of this general structure, that very soon you can draw it in your sleep!
* is a man
* was wearing a jeans
* was wearing a jacket
** the jacket had a zipper rather than buttons


Above, we said that <span style="color: blue>''sign'' has two subtypes, ''word'' and ''phrase''</span>. We will graphically represent that state of affairs as follows. A type that is connected by a line  to another type above it is said to be a <span style="color: blue>subtype</span> of the type above. From the point of view of the higher type we say that it is a <span style="color:blue>supertype</span> of the first type.
As there was only a single pickpocket, the police officer assumes that Jill and Jack are describing the same person. She gets on her radio and tells her colleagues to look out for a person meeting the following description:


[[File:Type-hiearchy-sign-word-phrase.jpg]]
the pickpocket


Let us, then, define the two subtypes.
* is a man
* has blond hair
* was wearing a jeans
* was wearing a jacket
** the jacket was black
** the jacket had a zipper rather than buttons


=== Feature Structures of Type ''word'' ===
10 minutes later, a man meeting this description is arrested and the stolen purse is found on him.


The definition of the type ''word'' is short. It is simply: ''word''.
'''Pickpocket Scenario 2'''


This may look funny, because it seems that according to that definition words have no grammatical properties. But remember that an object of type ''t'' has all the properties of all supertypes of ''t''. If ''t'' does not add any features or more specific values of the features to the information in its supertypes, then any object of type ''t'' still has all the properties of all the supertypes of ''t'' '''plus''' the information that it is an object of type ''t''.
The same scenario as above, just that now Jill and Jack describe the pickpocket as follows:


Applying this logic to the type ''word'', all words will have feature structures like the following:
Jill: the pickpocket


[[File:Word_features.PNG]]
* is a man
* has blond hair
* was wearing a jacket
** the jacket had buttons rather than a zipper


Note again that this feature structure differs in only one respect from the feature structure for ''sign'' which we gave above: the new feature structure is of type ''word''. This is the only information contributed by the type ''word'' in addition to the fact that ''word'' is a subtype of ''sign''. Because of this subtype relationship, the feature structure of type ''word'' inherits almost all its information from the feature structure of type ''sign''.
Jack: the pickpocket


<!--
* is a man
=== Feature Structures of Type ''phrase'' ===
* was wearing a jeans
* was wearing a jacket
** the jacket had a zipper rather than buttons


The type ''phrase'':
Again, the police officer assumes that Jill and Jack are describing the same person. The combination of the informtion in their descriptions yields the following new description:


[[File:Feature-structure-phrase.png | 600px]]
the pickpocket


Unlike the type ''word'', the type ''phrase'' adds two FEATURE-''value'' pairs to the information that it inherits from the type ''sign''. The first feature is DTRS (= DAUGHTERS) of type ''list'', which means that phrases may have daughters. For instance, sentences typically have the daughters NP and VP. One of these daughters is more important than all the others and this daughter is called the <span style="color: blue>head daughter</span>. This daughter is described by the feature HEAD-DTR, whose value is of type ''sign''.
* is a man
-->
* has blond hair
* was wearing a jeans
* was wearing a jacket
** the jacket had buttons rather than a zipper
** the jacket had a zipper rather than buttons


<!--
This combined description is inconsistent, because there is no jacket that can have both of the properties in the final lines at the same time. We say that if the unification of two or more sets of information is inconsistent, then '''unification fails.''' Or, to put it differently, when unification fails, then the two descriptions cannot be unified.  
=== The Head-Feature Principle (HFP) ===
<i>Phrases and their head daughters have identical parts of speech (POS) features.</i>


[[File:HFP.PNG]]
<span style="color: blue>Self-test exercises on unification</span>
-->


<!--
[[File:Unification-exercises.pdf]]<br>
=== Feature Structures of Type ''phrase'' with Inheritance ===
[[File:Unification-exercises-solutions.pdf]]


Feature structures of type ''phrase'' will therefore have the information in the previous representation plus all the information in feature structures of type ''sign''. The reason is of course that ''phrase'' is a subtype of ''sign''. All feature structures of type ''phrase'' must contain all of the following information:
== Word definitions ==


[[File:phrase_features.png]]
The second ingredient we need in order to track the details of the structure-building mechanism is word definitions.


If you now compare the filled-in feature structures of types ''word'' and ''phrase'' with each other, you find the following similarities and differences:  
We postulate that in order to be legitimate, every word must have the following structure:
-->
<!--
#Both have the SYN feature<!--s PHON and SYNSEM-->.
<!--#''phrase'' in addition has the features DTRS and HEAD-DTR which ''word'' lacks.
-->


<!--
[[File:Word_features.PNG|300px]]
Our system of types and subtypes thus encodes that words and phrases have phonological, syntactic, and semantic information, but that phrases have internal <span style="color: blue>phrase structure</span> which words lack. This difference reflects the fact that words are the smallest unit of syntax and cannot be broken down into smaller syntactic units, whereas phrases must contain at least one other syntactic unit.
-->
<!--
== Representing predicate-argument structure in  feature structures ==


In the exercises on Predicate-Argument Structure from Week 1, you were supposed to take a sentence apart into its predicate and 1-3 arguments of the predicate. The quiz software represented this information as follows:
We have seen many examples of this. There is nothing new here.  


Example: The story amuses the doctor.
But words belonging to the same part of speech may have to meet additional constraints that distinguish them from words of other parts of speech. Here is a list of those constraints for the word of the 7 parts of speech which our grammar contains:
 
[[File:Valence-words-1.JPG|200px|]]<br>
[[File:Valence-words-2.JPG|200px|]]<br>
[[File:Valence-words-3.JPG|200px|]]
 
Individual words add properties to the schema of their word class whose combination singles out a particular word. Here are some examples. Compare the structures below to the general format of words and the schema for their word class above.
 
[[File:Visits.JPG|200px]]<br>
[[File:Cats-him.JPG|200px]]
 
== Phrase definitions (again) ==
 
Now that we have words and know how to unify feature structures, we return to the definitions of syntactic phrases again. Last week, we already saw the definition of Head-Complement Phrases, repeated below:
 
[[File:H-C phrase 1.PNG|400px]]
 
== Building the head-complement phrase ''visits him'' ==
 
If our goal is to build the head-complement phrase, then we need 3 grammatical objects which we already have:
 
1. The word ''visits:''
 
[[File:Visits.JPG|200px]]
 
2. The word ''him:''
 
[[File:Him.JPG|200px]]
 
3. The schema for head-complement phrase
 
[[File:H-C phrase 1.PNG|300px]]
 
We proceed in two steps:
 
Step 1: Unify the feature structure of the word ''visits'' with the feature structure of the head daughter of the head-complement phrase:
 
[[File:HCF-plus-visits.JPG|700px]]
 
This results in the following partially specified head-complement phrase:
 
[[File:HCF-plus-visits-tree.JPG|400px]]
 
Step 1: Unify the feature structure of the word ''him'' with the feature structure of the non-head daughter of the head-complement phrase:
 
[[File:HCP-plus-visits-plus-him.JPG|600px]]
 
The result is the following head-complement phrase, where both daughters are now specified:
 
[[File:HCP-plus-visits-him-tree.JPG|600px]]
 
4. The Head-Feature Principle
 
Recall the content of the Head-Feature Principle:
 
[[File:HFP.PNG|300px]]
 
Since the head-complement phrase ''visits him'' is a phrase, it must satisfy the Head-Feature Principle. So, we need to unify the whole tree with the righthand-side of the principle. This result of this unification is the following tree:
 
[[File:HCP-visits-him-complete.JPG|600px]]
 
Now, the head-complement phrase ''visits him'' is complete. What could you do with it at this point?


Expected answer:
Predicate = '''x amuses y'''<br>
x = The story <br>
y = the doctor<br>
z = -<br>


Go to the [http://141.2.159.95:7003/wt/ Online Grammar] and click on the first main verb in the list on the left, the verb ''amuse''. A little tree with a node V[fin] at the top and '''amuse''' as its daughter should appear. Click on the V-node: now, you see the feature structure of type ''word'' that describes the word '''amuse''' in our grammar. Can you find the information '''x amuses y''' within the feature structure?
-->
<!--
Here is the file that we went through in class this week:


[[File:Valence.pdf|frame|Valence]] <br>


== Homework ==


For each part of speech where the valence may vary from one word to another, find one word for each option and draw a feature structure for it that includes the 3 valence lists. Use the format that you find on the handout! Bring the result to class next time.-->




Line 128: Line 176:
Navigation:  
Navigation:  
<div align="center">
<div align="center">
   [[Syntax_1_Wiki |'''Main page''']]|[[Syntax_1_Wiki:_Week_1| '''Week 1''']] |[[Syntax_1_Wiki:_Week_2| '''Week 2''']]|[[Phrases| '''Week 3''']]|[[Syntax_1_Wiki:_Week_4| '''Week 4''']]| '''Week 5'''|[[Syntax_1_Wiki:_Week_6| '''Week 6''']]|[[Syntax_1_Wiki:_Week_7| '''Week 7''']]  
   [[Syntax_1_Wiki |'''Main page''']] [[Syntax_1_Wiki:_Week_1|'''Week 1''']] [[Syntax_1_Wiki:_Week_2|'''Week 2''']] [[Phrases|'''Week 3''']] [[Syntax_1_Wiki:_Week_4|'''Week 4''']] '''Week 5''' [[Syntax_1_Wiki:_Week_6|'''Week 6''']] [[Syntax_1_Wiki:_Week_7|'''Week 7''']] [[Syntax_1_Wiki:_Week_8|'''Week 8''']]
</div>
</div>

Latest revision as of 06:22, 27 April 2022

Tracking the stucture-building process in detail

This week we are going study every detail of the licensing of phrases. For this purpose, we are going to study the interaction of the following concepts:

  1. Word definitions
  2. Phrase definitions (again)
  3. Unification (= the merging of feature structures)
  4. The Head-Feature Principle

Types

Follow this link to learn about the general properties of types.

Type-hierarchy.JPG

Unification

We begin with the concept of unification. It simply means that you combine the information that you have about an object from two or more sources. Or, to put it differently, you combine two descriptions of the same object. Here is an example.

The easiest way to understand unification, is to see it in action.

Pickpocket Scenario 1

Imagine that Jill and Jack are at the Frankfurt Christmas market together. At some point, they see a pickpocket stealing somebody's purse. By the time they have alerted the police, the pickpocket has disappeared. The police officer asks them for a description of the pickpocket and gets the following answers:

Jill: the pickpocket

  • is a man
  • has blond hair
  • was wearing a jacket
    • the jacket was black

Jack: the pickpocket

  • is a man
  • was wearing a jeans
  • was wearing a jacket
    • the jacket had a zipper rather than buttons

As there was only a single pickpocket, the police officer assumes that Jill and Jack are describing the same person. She gets on her radio and tells her colleagues to look out for a person meeting the following description:

the pickpocket

  • is a man
  • has blond hair
  • was wearing a jeans
  • was wearing a jacket
    • the jacket was black
    • the jacket had a zipper rather than buttons

10 minutes later, a man meeting this description is arrested and the stolen purse is found on him.

Pickpocket Scenario 2

The same scenario as above, just that now Jill and Jack describe the pickpocket as follows:

Jill: the pickpocket

  • is a man
  • has blond hair
  • was wearing a jacket
    • the jacket had buttons rather than a zipper

Jack: the pickpocket

  • is a man
  • was wearing a jeans
  • was wearing a jacket
    • the jacket had a zipper rather than buttons

Again, the police officer assumes that Jill and Jack are describing the same person. The combination of the informtion in their descriptions yields the following new description:

the pickpocket

  • is a man
  • has blond hair
  • was wearing a jeans
  • was wearing a jacket
    • the jacket had buttons rather than a zipper
    • the jacket had a zipper rather than buttons

This combined description is inconsistent, because there is no jacket that can have both of the properties in the final lines at the same time. We say that if the unification of two or more sets of information is inconsistent, then unification fails. Or, to put it differently, when unification fails, then the two descriptions cannot be unified.

Self-test exercises on unification

File:Unification-exercises.pdf
File:Unification-exercises-solutions.pdf

Word definitions

The second ingredient we need in order to track the details of the structure-building mechanism is word definitions.

We postulate that in order to be legitimate, every word must have the following structure: 

Word features.PNG

We have seen many examples of this. There is nothing new here.

But words belonging to the same part of speech may have to meet additional constraints that distinguish them from words of other parts of speech. Here is a list of those constraints for the word of the 7 parts of speech which our grammar contains: 

Valence-words-1.JPG

Valence-words-2.JPG

Valence-words-3.JPG

Individual words add properties to the schema of their word class whose combination singles out a particular word. Here are some examples. Compare the structures below to the general format of words and the schema for their word class above. 

Visits.JPG

Cats-him.JPG

Phrase definitions (again)

Now that we have words and know how to unify feature structures, we return to the definitions of syntactic phrases again. Last week, we already saw the definition of Head-Complement Phrases, repeated below: 

H-C phrase 1.PNG

Building the head-complement phrase visits him

If our goal is to build the head-complement phrase, then we need 3 grammatical objects which we already have:

1. The word visits: 

Visits.JPG

2. The word him: 

Him.JPG

3. The schema for head-complement phrase 

H-C phrase 1.PNG

We proceed in two steps:

Step 1: Unify the feature structure of the word visits with the feature structure of the head daughter of the head-complement phrase: 

HCF-plus-visits.JPG

This results in the following partially specified head-complement phrase: 

HCF-plus-visits-tree.JPG

Step 1: Unify the feature structure of the word him with the feature structure of the non-head daughter of the head-complement phrase: 

HCP-plus-visits-plus-him.JPG

The result is the following head-complement phrase, where both daughters are now specified: 

HCP-plus-visits-him-tree.JPG

4. The Head-Feature Principle

Recall the content of the Head-Feature Principle: 

HFP.PNG

Since the head-complement phrase visits him is a phrase, it must satisfy the Head-Feature Principle. So, we need to unify the whole tree with the righthand-side of the principle. This result of this unification is the following tree: 

HCP-visits-him-complete.JPG

Now, the head-complement phrase visits him is complete. What could you do with it at this point?







Navigation:

Retrieved from "https://www.english-linguistics.de/grammarparadise/wiki/index.php?title=Syntax_1_Wiki:_Week_5&oldid=5219"