Semantic roles and Grammatical Relations

The Phrase Structure model is a very useful tool for analyzing sentences. However, as we will see here, Phrase Structure rules by themselves cannot provide an adequate account of what speakers say. For example, the simple set of Phrase Structure rules can produce odd sentences like those in (1) and (2).

(1)  a #The young sausage likes the white dog.

       b #Mary sings a white cake.

       c #Asmall dog gives Mary to the young tree.

(2)  a *John likes.

       b *Mary gives the young boy.

       c *The girl yawns Mary.

Even though the rules seem consistent with what we know about the grammar of English, we see that they can produce unacceptable sentences. These sentences are unacceptable for different reasons. The # sign before the sentences in (1) indicates that they are semantically ill-formed, i.e. they cannot be given an acceptable semantic interpretation. The * sign before the sentences in (2) indicates that they are ungrammatical. In (2a, b) we feel there is a phrase missing, while (2c) seems to contain an extra phrase.

We will discuss these problems in detail in Lexical entries and well-formed clauses. For now the important point is that even though the Phrase Structure rules themselves may be correct, this will not necessarily ensure that the output of the rules is grammatical. Additional information is needed, information about the specific words which are used. This kind of information must be stored in the lexicon in some way.

Another type of complication that can arise is illustrated in (3). The PS rules could generate this sentence in two different ways. This means that the rules assign more than one possible Phrase Structure for this sentence, as shown by the two tree diagrams in (4). These two structures correspond to two different interpretations of the sentence. Can you identify the meanings which would be associated with these two structures?

(3) John pinches the young girl behind the tree.

The sentence in (3) is an example of STRUCTURAL AMBIGUITY; the sentence as a whole is ambiguous because it has two possible Phrase Structures, even though none of the individual words is ambiguous in this context.¹ Is it some problem with our PS rules that allows the same sentence to be assigned two different structures in this way? Not at all. This is simply a fact about English grammar. Sentence (3) really is ambiguous, so it is actually a good thing that our PS rules generate both of the structures shown in (4).

In providing two analyses for (3), our miniature rule system is successful in the sense that it produces the same results as a native speaker’s internal grammar. In contrast, when the rules produce sentences like those in (1) and (2) they are clearly failing to model what speakers actually say. In order to fix these problems we need to consider the unique properties of individual words, in particular of verbs. We will also need to refer to two aspects of sentence structure we have not yet discussed, namely SEMANTIC ROLES and GRAMMATICAL RELATIONS. We will begin this discussion by considering certain aspects of word and sentence meanings.

¹. In (4a) the PP is an adjunct describing the location of the event, while in (4b) the PP is a modifier indicating which girl was involved.

اخر الاخبار

اخبار العتبة العباسية المقدسة

جامعة أم البنين (عليها السلام) الإلكترونية تعلن فتح باب التسجيل للدراسات التبليغية والقرآنية

مستشفى الكفيل يعتمد أحدث التقنيات العالمية في عمليات زراعة القوقعة

مركز السيد جعفر الحلي يستقبل مدير صحة كربلاء للاطّلاع على خدماته المقدّمة للزائرين

قسم الشؤون الفكريَّة يقدِّم ندوة ثقافية لوفد شبابي من الموصل

المزيد

الآخبار الصحية

حالة صحية شائعة قد تُخفي "إنذارا مبكرا" للإصابة بالسرطان !

"أوميغا 3" صديق القلب.. هل يربك سكر الدم؟

بدائل لليمون.. 8 إضافات للماء تعزز فوائده الصحية

دراسة: محاولة متعمدة لنشر الإنفلونزا تنتهي بـ"مفاجأة"

المزيد

الآخبار التكنلوجية

سلامة الأطفال: سبع قواعد ذهبية للركوب الآمن بالسيارة

توقع خطير لماسك: الروبوتات ستتفوق على البشر من حيث العدد

دراسة تكشف عاملا غير متوقع يرتبط بزيادة خطر الإصابة بالتوحد

"ميتا" توقف وصول المراهقين إلى شخصيات الذكاء الاصطناعي ؟

المزيد

مواضيع ذات صلة

Anaphora vs. deixis

Grammatical case vs. semantic case

Semantic roles and Grammatical Relations Conclusion

Arguments and semantic roles

Constituency

Identifying meaningful elements Summary

Identifying meaningful elements within words

Identifying meaningful elements Identifying word meanings

Consequences of modifying Gunlogsons 2001 model

A case study of the semantics of clear - Factivity revisited

A case study of the semantics of clear - The analysis

A case study of the semantics of clear - Vagueness