19 Tree Diagrams

Mr. Kirti Azad Mandava

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Learning outcome

In the previous chapters we have learnt about constituents and phrase structure. So, we know that language has a structure that is based on neat arrangement of different constituents in a particular order. Each constituent in the structure has a specific function and shares certain relationship with the other constituents in the structure. Ferdinand de Saussure had explained these as syntagmatic and paradigmatic relationships. Syntagmatic relationships are linear relationships between constituents in a given structure. For instance, in a statement in English the verb comes after the subject and agrees with the subject for person, number and gender, as in the sentences given below. In (1) and (2) bird and fly; and in (3) and (4) fish and swim share a syntagmatic relationship.

(1) Birds fly

(2) The bird flies

(3) Fish swim

(4) The fish swims

And paradigmatic relationships are relationships between the constituents that belong to the same category and therefore share the same function in the sentence. For instance in (1) and (3) birds and fish share a paradigmatic relationship, and so do fly and swim.

These functions and relationships between categories and constituents in a phrase or any other structure may also be derived as a rule of the grammar. These can be represented in many ways, based on our own convenience for the sake of study. However, in Syntax there are two usual ways of representing the structure. They are tree diagrams and labelled bracketing. In this chapter we will learn how to represent the structure of a phrase, clause or a sentence using tree diagrams with examples from English.

Introduction

Tree diagrams and labelled bracketing are ways of representing the relationship between constituents. Look at the examples given below for representation of the sentence in (1).

i) Tree diagram

i) Labeled bracketing

 

[S [NP Birds] [VP fly]]

 

In (i) we see the representation of the sentence in (1) using a tree diagram. In (ii) we see the representation of the same sentence using labelled bracketing.

In labelled bracketing the sentence is put in square brackets. The constituents are enclosed in square brackets too. The label at the leftmost bottom corner of the bracket gives the information about the grammatical category of the constituent. In (ii) the first open square bracket comes with the label “S” and encloses the whole sentence, to indicate that “Birds fly” is a sentence. The next open bracket with the label “NP” indicates that Birds is a noun phrase. And the third open bracket with the label “VP” indicates that fly is a verb phrase. Every bracket that is opened has to be closed as well, so in (ii) we see that three open brackets equal three close brackets.

 

Now we shall understand basics of a tree diagram with the help of the example in (i). In the later sections of this chapter we shall learn to draw tree diagrams for different types of phrases, clauses and sentences. The tree diagram in (i) is given below again for easy reference.

 

1. Birds fly

 

This tree diagram as we know already is a notation of the structure of the sentence, in order to make it easy for us to understand and explain the structure. Here “S”, “NP” and “VP” are called nodes. The lines that move from S to NP and VP are called branches. There is a linear relationship and also a hierarchical relationship between the nodes and other constituents of the structure. So, we say that NP and VP are sister nodes as they share a linear relationship between them like that of sisterhood. They occur at the same level, and show syntagmatic relationship. Similarly S is the mother node and NP and VP are the daughter nodes, as they share a hierarchical relationship between them. We see that S dominates the NP and the VP. It is at a higher level than NP and VP. We also understand that NP and VP are the immediate constituents of S.

The triangle in this tree diagram indicates that this tree diagram does not show the complete analysis of the structure down to its last constituent. Instead it denotes that the analysis is incomplete and that this tree can be analyzed further down into other constituents of the NP and the VP. Wherever the analysis is complete we see branches and not triangles in the tree diagram.

Constituents of Phrases

We already know that there could be different kinds of phrases, such as noun phrase, verb phrase, prepositional phrase, adjective phrase and adverb phrase. Each phrase gets its name from the Head, which is the most important and obligatory constituent in the phrase. Therefore the noun is the Head in a noun phrase and there cannot be a noun phrase without the noun. Similarly the verb is the Head in the verb phrase; preposition is the Head in the prepositional phrase; the adjective is the Head in the adjective phrase; and the adverb is the Head in the adverb phrase.

In the previous chapters you have already studied the structure of the noun phrase and the verb phrase. In this section we shall learn to draw the tree diagrams for the structure of these phrases.

Noun Phrase

First let us look at the noun phrase. We know that the noun phrase may have just one constituent, the Head of the NP which is also the only obligatory constituent in the NP. The tree diagram for an NP with a single constituent will look like in the following example.

 

2. Birds

 

Here the immediate constituent of the NP is the N, which is the Head. And the immediate constituent of N is the noun Birds. This tree is complete as it has only branches and no triangle.

 

The NP can also have more constituents as shown below.

 

3. The birds

The NP here has the determiner and the Noun head as its immediate constituents. The immediate constituent of the determiner here is an article. And the immediate constituent of the Noun is the noun, birds.

 

We need to note that a there can be only one determiner in the structure of a noun phrase. It is possible for an NP to have another NP in its structure, but never would it have more than one determiner in the same NP. Let us consider two more examples of NPs with the determiner as a possessive and a genitive possessive.

 

4. My brother

In the tree diagram in (4), we see an NP with a possessive pronoun. There is just one determiner in that NP and it is represented in the structure. And in the tree diagram in (5) we see an NP with a genitive possessive. The determiner here has another NP, my brother, as a constituent, along with the genitive possessive marker‘s.

 

Now let us move on to a tree diagram with an Adjective phrase in the NP. An NP can have more than one adjective phrase in it. We shall look at the structure of the adjective phrase in more detail in a later section of this chapter.

 

6. The beautiful garden

In this tree diagram, the structure of the adjective phrase has not yet been analyzed completely. That is why we see a triangle. And in the tree below too the prepositional phrase has not been completely analyzed and therefore is denoted using a triangle.

 

7. All the three little birds in my garden

Now let us look at the model tree diagram for all the constituents of the NP.

 

8.

In the model tree diagram we see the obligatory constituent N and all the other optional constituents in an NP. Those preceding the Head are the pre-modifiers. And those that follow the Head are called post-modifiers. These pre-modifiers and post-modifiers add to the meaning of the Head. In an NP in English the categories of words that occur as pre-modifiers and post modifiers are given in the model in (8). Note that the order in which these occur is also fixed and is represented in the tree diagram. Among the pre-modifiers, there is usually not more than one pre-determiner, determiner, ordinal number and quantifier; but there could be more than one adjective phrase or noun phrase. And generally a prepositional phrase or clausal constituent occur as the post modifiers. There could be more than one prepositional phrase or clause in an NP. Often relative clauses occur as the clausal constituents in an NP.

Verb Phrase

 

In this section we shall look at the tree diagrams for the verb phrase. The VP is an immediate constituent of the sentence, along with the NP. The verb phrase can have the verb and other constituents such as an NP, PP, Adj P or Adv P. The VP has two obligatory constituents – Auxiliary (Aux) and the verb (V).

  1. wrote

The Aux has Tense as its obligatory constituent; and there may be other optional constituents such as Modal, Perfective aspect, Progressive aspect, and Passive as shown in the model tree diagram for a VP given below in (10), which could serve as a model tree diagram for the structure of a VP. Tense denotes whether the verb is in its past tense form or present tense form in the phrase, clause or sentence where it is used. If there is a modal in the VP, it is shown in its base form in the tree diagram. Then, when there is perfective aspect used in the verb phrase, the tree diagram indicates that there is HAVE used as a helping verb along with the past participle form of the main verb. Similarly for the progressive aspect, it is indicated that there is BE as the helping verb and the present participle form of the main verb. And so also for passive, it is shown that BE is the helping verb with the past participle form of the main verb.

And then the verb in its base form, is shown as the immediate constituent of V, always the sister node of Aux in the VP.

10. Might have been being written

A VP can also have other kinds of phrases as its constituents, as we have already said. In the tree diagrams from (11) to (14), we see an NP, PP, Adj P and Adv P as the constituents of the VP respectively. So, the VP in English can take any other kind of phrase as its constituent, as stipulated by the word-order. However, these are always optional constituents of the VP. There could be more than one of these phrasal constituents within the same VP. An example of a VP with two NPs is shown in the tree diagram in (15). Apart from these, a VP may also have a clausal constituent as shown in a later section of this chapter.

 

11. See her

15. Buy her a ring

Prepositional Phrase

 

The prepositional phrase begins with a preposition and usually has two obligatory constituents – a preposition Head and an NP. Sometimes it may have other constituents too, most probably another PP and generally not any other kind of phrase. The examples of tree diagrams for the structure of PP are given in (16) and (17). In (16) there are only the obligatory constituents – the immediate constituent of the Head, P, is the preposition in and the NP is the garden. And in (17), we see that there is an optional constituent along with the two usual obligatory constituents of the PP – the P Head with the preposition from, and the PP, behind the curtain, are the immediate constituents of the PP, and then further the embedded PP also has its obligatory constituents with the preposition behind, as the P Head and the curtain as the NP.

 

16.In the garden

17. From behind the curtain

Adjective phrase

 

The adjective phrase has the adjective as its Head as its only obligatory constituent, as shown in the tree diagram in (18). It may have other optional constituents such as degree, which may sometimes be called an intensifier. In the tree diagram in (19) we see an example where very is the intensifier and beautiful is the adjective.

 

The adjective phrase may also have other phrases as its optional constituents. In the tree diagram in (20), we see the adjective fond, as the adjective Head and the PP, of films, as the optional constituent. And in the tree diagram in (21) we see that an adverb phrase may also be an optional constituent of the Adj P. Here, the adverb phrase, smartly is the optional constituent and the adjective dressed is the obligatory constituent adjective Head.

 

 Adverb phrase

 

In the adverb phrase, there is only one obligatory constituent just like in the adjective phrase. It is the adverb Head. In the tree diagram in (22) we see an example of this, where the adverb luckily is the adverb Head. The adverb phrase can also have an obligatory constituent, the degree or intensifier, as in the tree diagram in (23), where very denotes the degree and loudly is the obligatory adverb Head.

Clausal constituents

 

So far we have looked at the representation of the constituents in different kinds of phrases in a tree diagram. Now let us look at the tree diagrams for clauses and sentences. Sentences may have just one clause or more than one clause. First we shall look at the tree diagrams for single clause sentences and then for sentences with more than one clause.

Single clause sentence

 

When a sentence has just one clause in it, it will have the NP and the VP as its immediate constituents, like we have seen in an earlier section. In (24) we see an example of the tree diagram for a single clause sentence. We see that all the constituents are analyzed right up to the last constituents. Therefore we see only nodes and branches and no triangles. Notice that all the phrases in the NP and VP are fully analyzed and represented to complete the tree diagram for the sentence. The sentence, I love Syntax, has I as the NP and love syntax as the VP.

 

24. I love syntax

Sentence with more than one clause

 

We already know that the sentence has an NP and a VP as its immediate constituents. So, any additional clausal constituents in the structure have to be part of either the NP or the VP or both. In (25) we see an example of a tree diagram for a clausal constituent in the NP. The clausal constituent is who is standing there. It is a post modifier which adds to the meaning of the noun Head, man. So, this sentence has the man who is standing there as the NP and is my brother as the VP. The clause, who is standing there, in NP is represented as another S within the NP which in turn has who as its NP and is standing there as its VP, as shown in the tree diagram.

 

25.The man who is standing there is my brother.

Now we shall look at an example for a clausal constituent in the VP in the tree diagram in (26). This sentence has I as the NP and said that he will come tomorrow as the VP with the relative clause that he will come tomorrow as a clausal constituent in the VP. This clausal constituent is analyzed in the tree diagram as the , since it has the complementizer that and S with the clause he will come tomorrow as its constituents.

 

26. I said that he will come tomorrow

Binary trees

 

In the last sections, we looked at trees for various phrases. The trees that grow down and to the right are right-branching, and trees that grow down and to the left are left-branching. The direction of branching reflects the position of heads in phrases. So the right-branching structures are head-initial, whereas left-branching structures are head-final. While English is more right-branching; some languages such as Japanese and Telugu are almost fully left- branching (head-final).

 

In the Generative tradition of Linguistics, started by Noam Chomsky, all branching is binary. We will learn X-bar schema in a later chapter and you will see that there is a specifier (spec) and a complement (comp) for any head and the branching is always binary.

 

In the example in Figure 27, we can see the structure of a binary tree.

 

27. Binary branching tree

 

Phrase structure Rules

 

We have been using tree diagrams to represent the structure of various phrases, which allow us to describe the syntactic structure of the phrase under study. The Phrase structures are used to break down a natural language sentence into its constituent parts, also known as syntactic categories, including both lexical categories (parts of speech) and phrasal categories.

The first rule reads: An S (sentence) consists of an NP (noun phrase) followed by a VP (verb phrase).

The second rule reads: A noun phrase consists of an optional Det (determiner) followed by an N (noun).

The third rule means that an N (noun) can be preceded by an optional AP (adjective phrase) and followed by an optional PP (prepositional phrase). The round brackets indicate optional constituents.

 

1. S → NP VP
2. NP → (Det) (AP) N (PP)
3. VP → (Aux) V (NP)
4. PP → (Deg) P (NP)

Summary:

In this chapter, we have learnt that tree diagrams are essential tools for linguists working in the area of syntax. Tree diagrams capture the sentence structure and help us understand the relationship amongst the constituents of the phrase. We have also discussed that in building up the tree diagrams, we have the head of a phrase and it branches out to take either a specifier or a complement. All phrases are characterized by an obligatory head and derive their name from this head. While working out the tree representation, one could work it down to the level of words or to the level of an unspecified complement, in which case it can be left as a triangle. In the Generative framework, branching of nodes is always binary. The phrase structure rules provide an essential structure of all the sentences in a language by spelling out the specifier and the complements for each phrasal head. The trees will conform to the phrase structure rules.

you can view video on Tree Diagrams
Reference
  • Alexiadou, A., Haegeman, L. & Stavrou, M. 2007. Noun phrase in generative perspective. Berlin: de Gruyter
  • Chomsky, N. 1957. Syntactic structures. The Hague/Paris: Mouton.
  • Chomsky, N. 1970. Remarks on nominalization. In R. Jacobs and P. Rosenbaum (eds.), Readings in English Transformational Grammar, 184–221. Waltham: Ginn.
  • Comrie, B 1989. Language universals and linguistic typology : syntax and morphology, 2nd edition. Oxford: Basil Blackwell.
  • Fabb, Nigel. 1994. Sentence Structure. London: Routledge.
  • Fowler, R. 1971. An introduction to transformational syntax. London: Routledge and Kegan Paul.
  • Jackendoff, R. 1977. X-bar-syntax: A study of phrase structure. Linguistic Inquiry Monograph 2. Cambridge, MA: MIT Press.
  • Haegeman, L & Guéron, J., 1999. English Grammar: A generative perspective. Oxford: Blackwell.
  • Haspelmath, M., M. Dryer, D. Gil, and B. Comrie (eds.) 2005. The World Atlas of Language Structures. Oxford: Oxford University Press.
  • Huddleston, R. & Pullum, G. 2002. The Cambridge Grammar of the English Language. Cambridge: Cambridge University Press.
  • O’Gardy, W et al. 1991. Contemporary Linguistics: An Introduction. New York: St Martin’s Press.
  • Radford, A., 1997a. Syntactic theory and the structure of English. Cambridge University Press.
  • Radford, A., 2004. English Syntax: An Introduction. Cambridge University Press.
  • Thomas Linda. 1993. Beginning Syntax. Oxford: Blackwell.
  • Wekker, Herman and Liliane Haegaman. 1985. A Modern Course in English Syntax. Kent: Croom Helm.
  • http://web.uvic.ca/~ling48x/ling484/notes/structures.html.
  • http://lx16.yolasite.com/resources/how-to-build-a-tree-diagrams-answer-key- for-homework- and-review1-130506224754-phpapp02.ppt.
  • http://people.umass.edu/scable/LING201-SP13/Slides-Handouts/Syntactic-Trees.pdf.