The Difference between Deep Structure and Surface Structure and its Importance 

1. Introduction
Generative linguistics has for over 60 years made remarkable impact in language study, and it set the pace for modern linguistics due to its influence (direct or indirect) on recent theoretical developments. However, still in the past 60 years, it has been under series of criticisms which Mohammed says include “ambiguity resulting from integration with other fields” like “mathematics and logic”, “rise of sub-schools like generative semantics, frequent modifications of the proposed theory” etc. (80-86); however, most of the claims are hardly sustainable as the theory continues to remain relevant in modern linguistics. Chomsky first introduced the generative grammar through his book Syntactic Structures published in 1957. The early generative study was based only on grammar but subsequently its scope of application expanded to accommodate phonology and semantics, and it spread to non-linguistic fields like psychology (Zheng, 1681).

The theory has constantly been updated in other for it to account for areas of language studies later discovered to have been neglected. That led to the proliferation of generative concepts or sub-categories like the Phrase Structure Rule, the X-bar theory (Aarts, Radford, Carnie, 2002.), the Government and Binding Theory (), and the Minimalist Theory ().
Generative grammar is a linguistic theory that considers grammar as a system of rules that generates a combination of words that form grammatical sentences in a given language (). A grammatical sentence is a combination of words that makes sense. That is, a sentence is ungrammatical if it does not convey meaning or if its structure is unconventional as to be free of misinterpretation that could result from defying rules governing sentence construction. For example, “There are two boy in the garden”. This sentence is ungrammatical not only because it lacks concord, but it is not clear whether are should be is or boy should be boys.  Generative grammar explains that through some transformational processes, interlocutors create sentences from their thoughts in other to convey certain meanings in conversations. Transformational grammar was the earlier name used for the concept (owing to the claim that sentences undergo transformation in order to relate different ideas), which is why it could also be called transformational generative grammar. The transformation occurs because new expressions are generated through transformation of grammatical structures.

2. Deep and Surface Structure

Have you ever experienced a situation where you felt words were not enough to exress what you have in mind? If yes, you already understand what is the difference between deep structure and surface structure (Institute of Clinical Hypnosis)
Deep structure is what you can say to your self – what you have in mind. Surface structure is what you provide for your listener to understand what you have in your mind. From the abundance of linguistic items at your disposal, you pick a few to relate an idea. The more detailed experience is in the deep structure. In the process of transforming the deep structure into the surface structure, some information are left out. Only what is believed to provide a clue to the detail or which is enough to elicit the perlocutionary act will be provided. And in some cases one may reframe a sentence several times to be sure his listen gets the exact intended information. For instance the statement Everybody likes me. This involves generalizations, distortions and omissions that only the speaker is aware of. It is important to understand the deep structure because a deep structure would never be represented the same as the surface structure. So far as that is true, deep structure will remain relevant in conversation through ages.

The concept of D-structure and S-structure is not a theory or sub-theory by itself. From the background of Generative Theory, Chomsky points out that there are two levels of syntactic structures: the deep structure and the surface structure. Harris (1972) said that the distinction between deep and surface structure has been arguably considered implicit but was ignored by historical linguists until it resurfaced in Generative Linguistics (267). Not much of it is mentioned in most recent works; but fundamentally, its impact is still evident in how sentences are manipulated to form different structures and semantic impressions. The two structures (deep and surface) do not exist independently. For every sentence made, there is a D-structure and S-structure relationship – as displayed below. For one to disregard the concept is only to pretend not to notice its relevance, or to deliberately (for whatever reason) disregard the relationship between the notion and its name. Through phrase structure rules, the deep structure is created in the subconscious of the speaker from his/her language of thought. Through transformation, the deep structure is restructured to enhance its interpretation. That final structure which is used in conversation is the surface structure.




XP rule
Deep Structure
Transformation
Surface Structure
Deep structure is defined as the underlying syntactic structure of a sentence. “It is an abstract representation that identifies the ways a sentence can be analyzed and interpreted” (Nordquist, 2018). It is the first level of syntactic structure which contains the linguistic items needed to create and understandable surface structure. It is also important for semantic interpretation. He added that the deep structure facilitates grammatical relations such as subject and object relationship, it enables lexical insertion; it enables transformation, and semantic interpretation.

The surface structure is the final output of the syntactic activity that begins at the deep structure level. It is the second level of syntactic structure.
You pushed the chair. (active)
The chair is pushed by you. (passive)
Push the chair. (imperative)
Schlesinger (1979) examined the distinction between cognitive structures, semantic deep structures and the surface structure. The Cognitive structures usually consist of a continuum sections which are classified into deep structure relations (320). As much as at extremes, there appear to be identifiable distinctions of linguistic cases between cognitive and deep structure, Schlesinger points out that such distinctions might be ignored as the separation is obscure. His study was on the with-phrase to examine the instrumental and comitative perspective of the phrase at the cognitive structure level and deep structure level. The study recognizes three structure levels with the deep structure in the middle. The deep structure refines the cognitive structure into the first level of grammar application which is further transformed to produce the surface structure. Schlesinger observed that the INSTRUMENTAL and COMITATIVE cases expressed in with-phrases below show great difference, but that Walmsley (1971) (in Schlesinger (1979)) takes them as subcategories of the same deep structure:
(1) John cut the meat with a knife (instrumental) (John used the knife to cut the meat).
(2) John burgled the house with an accomplice (comitatitive) (John and an accomplice burgled the house).
(3) John won the appeal with a highly paid lawyer.
(3) is a sentence that shows neither instrumental nor comitative in that the lawyer could not be used the same way as knife in (1) or as an accomplice in (2). While (1) and (2) can represent two extremes of the cognitive structure continuum, (3) will be located somewhere between. This idea led to the identification of three levels of structure:

Cognitive structure agent…………...instrument………………..manner



Deep structure AGENTIVE INSTRUMENTAL- MANNER
COMITATIVE

Surface structure subject with-phrase   adverb

3. The importance of deep structure

This question is more or less to say whether it is still important to discuss the concept of deep structure and surface structure. The generative grammar seems to a large extent to be under attack, and so are its concepts. The surface structure and deep structure syntactic concepts were developed by Chomsky in 1965. It formed part of the transformational grammar activity that could happen in the use of language, especially in relating the abstract form of language with the physical or perceptible analytical form.
It seems not many linguists of recent times find the deep and surface structure concept so important as to continually occur in generative discusses. They hardly include it in their works; sought of saying “Enough of this deep/surface stuff”.  Generativists like Aarts (2007) Carnie (2002) and Sobin (2012) did not discuss it in some of their works on generative syntax.

3.1. Grammatical rules and grammatical well-formedness conditions

Nordquist identifies four major properties of D-structure: grammatical relations, lexical insertions, transformation and semantic interpretations; which he said do not necessarily go together. The conditions that guide grammatical rules application and sentence well-formedness are not devoid of these four properties. Grammatical items are linked in certain patterns like Det+N       NP, NP+VP      S. It is not an acceptable relationship if N comes before Det. Therefore, syntagmatic relationship that occurs in grammatical expressions has its root in D-structure. Lexical insertions

3.2. Relevance of deep and surface structure grammar in translation

Wu says that “Translation is an activity of expressing something in another language without changing its original meaning” (396). Through translation, an idea originally produced in one language is reproduced in a different language so that speakers of the translated language could be communicated to. The process is not as easy as word to word replacement. It involves complex processes that includes consideration of syntactic structures and semantic processing of the two languages.
Nida uses Chomsky’s deep and surface structure concept to produce a model for translation. The concept enables translators to decode the Source Text (text from the original language) and encode the Target Text (text in the language to be translated into). They analyze the surface structure of the ST to obtain the basic elements of the deep structure which are restructured syntactically and semantically and reproduced in the surface structure of the target language (in Wu, 397-398). Nida uses this diagram to illustrate the concept of translation using the deep structure and surface structure concept.




      A (source language) B (target language)


  (analysis)       (restructuring)


(X language) (transfer)        (Y language)

3.3. The importance of deep and surface language structure in Second language and foreign language usage

Since Nida’s idea of enabling translation through the surface and deep structure model, it is therefore very important instrument in second language and foreign language speaking. Nigeria speakers for instance, have developed different English language features that bring about what is called Nigerian English. This Nigerian English variety is mainly as a result of mother tongue influence. Even Nigerians that have formed a repertoire that enables them to think in English are not entirely free from mother tongue influence because the repertoire is made from expressions translated from the speakers’ mother tongue. There are multiple deep structures in the sentence formation of foreign language usage. English as Second Language (ESL) speakers for instance basically think in their first language. That means there is the activity of forming a second deep structure from their first language before a reproduction of another deep structure of that will be translated into the English surface structure sentence. Therefore there are two stages of deep structure to surface structure activity. It begins with the production of the deep structure of the first language to its surface structure, then the deep structure of the foreign language (of communication) to the surface structure. If this complex activity must be done for a nonnative speaker to communicate in English, the Deep Structure concept is still relevant and it will always be relevant.
Aarts (2001) did not mention the terms deep structure and surface structure in his English Syntax and Argumentation just like he did not mention that his approach is generative/transformational grammar even though his reference to Chomsky’s work settles that. He however explained the transformational characteristic of the sentence structure and its relation with the subconscious and grammaticality. He said, for example, that there are different ways to ask someone to open the window: ‘Can you open the window, please’, ‘Could you open the window, please’, ‘I was wondering whether you could possibly open the window’, and ‘Open the window’ (3). Also, a sentence could be ambiguous, grammatical or ungrammatical (4). It is in the subconscious that one detects any syntactic or semantic problems before fixing them by rearangement, removal or replacement of the words that form the sentence.  Modification of a word to change its meaning or to make it grammatical is a transformational process that involves the Deep Structure.
The deep structure is important in learning other languages. Learners of other languages always recreate the deep structures to be able to communicate in the appropriate surface structures. In fact, learners sometimes reproduce what should be the deep structure in their actual utterance, and the listeners (proficient in the language) are left to take the content as given, transform it into the surface structure before interpreting it and responding to it.
In Nigeria for instance grammatical and semantic errors are not so much a crime because they have become common even though they are not out rightly approved. For instance a sentence like I see you (I saw you/I see you) or a kind of pidgin has to be processed by engaging the deep structure to produce a surface structure that could make clear the meaning of the expression. Context comes into play in such situations. A task of subconscious activity will be adopted to figure out the real intended meaning of the not only ambiguous statement but also vague.

3.5. Deep structure and semantics

Syntactic constructions are not done separate from there expected meaning. There is a relational distribution between syntax and semantics which happens in the deep structure. In dealing with ambiguity for instance, the surface structure takes one form to represent multiple semantic notions, while in the deep structure, they are separately represented. For example, the love of God is good. There are several possible meanings that can be generated from this ambiguous statement even though surface structure provides only one structural form. This sentence could mean these three: It is good for people to love God, It is good when God loves people and when love is an NP complement similar to The Lord is good. Neither of the two diagrams below can be used in any clear way to represent any of the three deep structure semantic possibilities.




1.           2.






            The love         of God    is good.
Similarly, the sentences John is eager to please and John is easy to please can have same surface structure, but the deep structure provides separate structures for the two, whereby John is the subject of the verb please in the first sentence, and in the second sentence, John is object of the verb please. Therefore, it is through contextual recognition of the meaning intended, that a lucid surface structure would be formed.

4. Deep structure and Pidgin

Not bothering on the evolution of pidgin, we would concentrate on its use in Nigeria. Over the years, propositions have been made to replace British English with Nigerian Pidgin in national language use, and the effort has led to its recognition at regional level as it is even used in media broadcast.
Having looked at the relevance of the deep structure and surface structure characteristics of grammar in English and upholding the view that its relevance has not in any way fallen, we decided to consider how it applies in Nigerian Pidgin. Mafeni (1971) in Oziza (2015, 11) observed that “…the grammatical categories of English do not necessarily fit the patterns of Pidgin”; for instance, plural marking is largely indicated by adding dem to the noun, as in The draiva dem de kom for The drivers are coming (Oziza, 2015, p11). We observed also from the example that the –ing verb form is not indicated by affixation in Pidgin. Instead, the word de is used. This suggests that the syntactic relationship between deep structure and surface structure in English and NP would not be similar. With this in mind, how can the deep structure of the Nigerian Pidgin be accounted for? 
In English, transformational process is employed to produce different grammatical structures for specific semantic realisations, it does not look the same in Pidgin. The form that should represent the deep structure is produced at the level of use or interaction. For example inflexions are not used to indicate tenses or subjunctives in Pidgin.
a. I no go school yesterday (I didn’t go to school yesterday).
b. If I be goat, slaughter me (If I be a goat, slaughter me).
Sentence a. shows that Pidgin does not depend on suffixation or inflexions to indicate tense, the adverb or additional verb words are used. De in c. could be translated as am but not in d. because the English translation does not contain the verb am. To a large extent, this corroborates the criticism that the Nigerian Pidgin does not have a “generally acceptable model” (Balogun 2012, p. 96).
c. I de go market. (I am going to the market).
d. I de go market everyday (I go to the market everyday).
e. I go market yesterday (I went to the market yesterday)
Considering the verbal limitation of Pidgin, the sentences Choji killed the snake and the snake was killed by Choji can hardly be expressed by their different structures. The two are translated in pidgin as Choji kill the snake which could more likely represent the deep structure in English. Therefore, in as much as the deep structure remains relevant in modern linguistics, its application in Nigerian Pidgin is rather complex as there is limited room for syntactic transformation.
5. Conclusion
The deep structure is a linguistic concept that began over 60 years ago, but it has not lost its relevance in modern linguistics despite how much neglected it seems. It is a little too abstract to engage with, that is possibly why more recent linguists tend to stay away from it. However, its contribution to realizations such as the sorting of underlying structures at the deep level will still be in use. We have seen its relevance in cognitive linguistics and grammar, and this study has further buttressed that meaning cannot be complete if the deep structure of a language does not relate with the surface structure. It is important that modern linguists get a little more engaged in developing the concept to make it clearer rather than be restricted to the physical forms that could in some instances be structurally misleading.
 
Works cited
Aarts, Bas. English Syntax and Argumentation, Third edition. Palgrave Macmillan, 2001.
Balogun, Temitope Abiodun. “In Defense of Nigerian Pidgin”. Journal of Languages and Culture, vol. 4, issue 5, pp. 90-98, 2013.
Carnie, Andrew. Syntax: a generative introduction , second edition. Blackwell Publishing Ltd 350 Main Street, Malden, MA 02148-5020, USA, 2002.
Harris, Martin. “Problems of Deep and Surface Structure, as reflected in a diachronic analysis of the French verbal system”. Journal of Linguistics, vol. 8, pp 267-281, 1972.
Mohammed, Ahmed. “An Account of Rise and fall of Transformational Generative Grammar TGG: A Descriptive Study”. The International Journal of Indian Psychology, Volume 3, Issue 1, No.4, December, p 76 – 99, 2015,.
Nordquist, Richard. “Definition of Deep Structure, Glossary of Grammatical and Rhetorical Terms”. www.thoughtco.com 2002.
Oziza, Rose Oro. “Aspects of the Syntax of Modern Nigerian Pidgin”. Selected Proceedings of the 44th Annual Conference on African Linguistics, ed. Ruth Kramer et al., 11-16, Somerville, MA: Cascadilla Proceedings Project, 2015.
Schlesinger, I. M. “Cognitive Structures and Semantic Deep Structures: the case of the instrumental”. Journal of Linguistics, vol. 15 issue 2, pp 307-324, 1979.
www.instituteofclinicalhypnosis.com
Zheng, Yingxue. “The Application of the Individual Teaching Based on Generative Phonology in the University”, Theory and Practice in Language Studies, Vol. 3, No. 9, Academy Publisher, September 2013, p. 1680-1684,