Practical Grammar 6

Governable grammatical functions

In linguistics, a head governs a property of another expression if it requires this expression to have that property. Governable properties include grammatical functions, cases, and particular prepositions.

In Lexical-Functional Grammar, the governable grammatical functions are those which may be listed in the PRED values of meaningful words The textbook (p. 21) gives a complete list:

Governable grammatical functions: SUBJ, OBJ, OBJ-θ, OBL-θ, POSS, COMP, and XCOMP.

There are other GFs, for instance TOPIC and FOCUS, but heads cannot govern those.

The Greek letter θ (= theta) in the functions OBJ-θ and OBL-θ is an abbreviation. It stands for the name of a thematic role (the thematic roles are listed on p. 13 in the textbook).

Here are some comments on the functions other than SUBJ and OBJ:

• OBJ-THEME: the GF of the second NP object of a ditransitive verb like give (e.g. give Mary a present)
• OBL-LOC: the GF of a locative complement of a verb like sit (e.g. sit at the window)
• OBL-BEN: the GF of a benefactive PP (bake a cake for Mary)
• POSS: the GF of the possessor within an NP (e.g. my book)
• COMP: the GF of a finite complement clause complement of a verb like say (e.g. said that Mary called)
• XCOMP: the GF of non-finite phrases with understood subjects (e.g. Lilly tried to leave)

The Completeness and Coherence Conditions

Words may specify in their lexical entries that they govern one or more GFs. These GFs are mentioned in the word's PRED value, e.g.

(1) disappear: [PRED   'DISAPPEAR<SUBJ>']
(2) see: [PRED   'SEE<SUBJ, OBJ>']

This means that the verb disappear governs one GF, namely a SUBJ and the verb see governs two GFs, a SUBJ and an OBJ. As a result, these verbs must appear with exactly these GFs, neither more, nor less. This is ensured by the following two principles:

The Completeness Condition (p. 21)
All governable functions which are part of the value of a PRED feature must be present in the local f-structure. All functions that have a θ-role must themselves have a PRED value.

This is the "nor less" part from above: the f-structure of a PRED must contain at least the GFs which it selects in its PRED value.

The "neither more" part is stated in the

Coherence Condition (p. 22)
All governable functions present in an f-structure must occur in the value of a local PRED feature. All functions that have a PRED value must have a θ-role.

So, an f-structure is complete and coherent only if there is a 1:1 relation between the GFs listed in its PRED value and the actual GFs present in the f-structure! If this is not the case, then the f-structure is ill-formed.

Governable features

Above, it was said that not only the GFs but also other properties of its dependents can be governed by a selecting head. These include inflectional features like PER, NUM, and CASE. In other words, a head can require that its dependents have particular values for such features. In this section, we will see how this is done.

In Week 3, we already saw how features can be added to words. There we formulated lexical entries like the following:

this D
     [PER:3,
      NUM:sg];

We can do the same in defining pronouns:

she N
    [PER:3,
     NUM:sg,
     CASE:nom];

me N
   [PER:1,
    NUM:sg,
    CASE:acc];

We now need to ensure that only expressions with features like those of she can act as subjects of a verb like disappears. This is easy to accomplish: in order for disappear to impose feature values on its SUBJ, it can simply refer to the f-structure of that SUBJ, as follows:

disappears D
           [PRED   'DISAPPEAR<SUBJ>',
            SUBJ   [...]];

The presence of a SUBJ in the verb's f-structure is guaranteed by Completeness: since the verb selects a SUBJ in its PRED value, there has to be a SUBJ. And that SUBJ has its own f-structure. Any feature-value pairs in the place of the dots inside the embedded brackets above must be present in the f-structure of the SUBJ. This is an example of feature government.

Exercise 6.1

1. Go to https://xlfg.labri.fr/ and log in.
2. Open your version of Grammar 5.
3. To the verb disappears, add constraints that ensure that its SUBJ is third person singular and bears nominative case. Note that the verb in this system does NOT need to have the features PER and NUM itself! Rather, the verb form with the shape disappears requires its SUBJ to have particular values for these features and disappear requires its SUBJ to have different feature values.
4. Add the following test sentences:

She disappears

*We disappears

*Her disappears

5. Parse.

Macros

The treatment of the present tense forms other than the third person singular is more complicated. An unmarked form like disappear can be 1sg, 2sg, 1pl, 2pl, and 3pl. We need an efficient way of encoding this information. To this end, we introduce macros, i.e. abbreviations that we define.

We start small. Since there are so many third person singular nouns and determiners, we often have to write the following:

[...,
 PER:3,
 NUM:sg,
 ...]

This is annoying. To make life easier on us, we can define a macro which allows us to encode this information in a shorter way. A macro is a statement of the following form:

@macro-name: attribute:value;

You can also have several attribute-value statements on the right. The statements are separated by commas. We will see examples presently.

So, let us define our first two macros:

@s: NUM:sg;
@p: NUM:pl;

The first macro says that we can use the expression "@s" to abbreviate "NUM:sg".

Here are macros for different person values (be sure to use the underscore between @ and the number, as xlfg does not accept a number that directly follows @!):

@_1: PER:1;
@_2: PER:2;
@_3: PER:3;

It gets better: the definition of one macro may contain other macro calls (a macro call is the use of a macro name in an environment where that macro is not defined). The examples below illustrate this:

@_1s: @_1, @s;
@_2s: @_2, @s;
@_3s: @_3, @s;
@_1p: @_1, @p;
@_2p: @_2, @p;
@_3p: @_3, @p;

The first line says that "@_1s" is short for "@_1, @s", which, when we unpack the two macros on the right means that "@_1s" is short for "PER:1, NUM:sg". And the same for the five other person-number combinations.

Finally, there comes another cool feature. Macros can contain the symbol "|" (= stroke), which means "or". Here is an example:

@_12: PER:1|2;

Of course, this says that "@_12" is short for "the PER value is either 1 or 2".

Now we have all the ingredients to say in a short manner that forms like disappear are compatible with subjects that are non-third person singular. We can do this with the macro "@non3s":

@non3s: [@_12] | [@_3p] ;

Read this carefully: "@non3s" is the name of the macro. This name abbreviates a feature structure which is either first or second person or it is third person plural. Note that these are precisely the person-number combinations other than third person singular!

Exercise 6.2

1. Go to https://xlfg.labri.fr/ and log in.
2. Open your version of Grammar 5.
3. Add all the macros above in the Declarations editor.
4. Add the verb disappear to the lexicon and add constraints that ensure that its SUBJ is non-third person singular and bears nominative case.
5. Add the following test sentences:

I disappear

You disappear

*She disappear

*I disappears

*You disappears

She disappears

I disappeared

You disappeared

She disappeared

6. Parse.

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