Syntax 1 Phrase Structure In the lecture on Plato s problem in the previous module we pointed out that the stream of speech is a continuum in the physical acoustic record You can get a sense of the physical continuum by looking at the acoustic record in a sound spectrographic recording of speech or more simply by listening to people who are speaking a language that you do not know In the latter case see if you can hear breaks between phrases and words Probably not The analysis of the stream of speech into phrases words and individual sounds is all done in the mind of the speaker that knows the language and is done by the speaker s internalized grammar Since this analysis is neither taught nor learned we assume it is built in or innate in the language faculty in the mind Since the analysis is not consciously done by the speaker to study it we must develop some tools of analysis We will begin by looking at how we might identify the phrasal constituents in sentences The Movement Test In looking at the jungle ahead of them hunters on safari will not see the tiger until it moves This movement will not only pick out the tiger from the trees and brush but if the tiger moves back into another part of the jungle it will also identify the area it has moved around Similarly in looking at sentences if something moves it not only picks itself out as a moveable unit the tiger in the sentence but it identifies the unit of jungle it moves around Consider the examples in 1 and 2 1 John can swim 2 Can John swim Sentences 1 and 2 are related as statement and question Let us assume that the question in 2 is derived from the statement in 1 by movement of can around John If we add a few more examples with will may must should etc we find that they all move around John in the same way to derive questions from statements Self Assessment Exercise 1 Try it right now Construct pairs of sentences like 1 and 2 with will may must should etc in place of can If we posit a rule that inverts the first two words in a sentence to form a question it will work for 1 and 2 and presumably for the sentences you created in the exercise above However it will not work for sentences like those that follow 3 The man can swim 4 The man in the canoe can swim 5 The man who lives upstairs can swim 6 The man and the woman can swim Self Assessment Exercise 2 Try it right now Construct corresponding questions for 3 6 above by moving can Assure yourself that will must etc move in the same way that can does in these sentences With these several examples we have identified two units in sentences Call the unit that moves an auxiliary AUX and the unit it moves around a noun phrase NP We can also identify the unit left behind to the right of the AUX Call what is left behind a verb phrase VP We can see in 7 and 8 that VP can consist of more than one word 7 John will swim the English Channel 8 The man who lives upstairs can drive a truck Self Assessment Exercise 3 Try it right now Construct corresponding questions for 7 8 by moving the AUX around the NP Identify the NP and the VP that is left behind Phrase Structure Rules Now we are in position to set out the phrase structure PS rules for the constituents identified so far We start with sentence S 9 S NP AUX VP 10 AUX can will may must etc We have seen that the NP is the constituent that the Aux inverts with to form a question That is the rule is structure dependent It cannot be defined on the number of words but must be defined on structures A test for the constituent NP is to put it at the front of a sentence followed by an AUX and see if the AUX can move around it to the beginning of the sentence to form a question There are other tests to determine if a constituent is NP Try substituting a pronoun he she it for the whole constituent If you can the constituent is an NP Self Assessment Exercise 4 Try it right now For all the NPs in the preceding examples see if you can replace them with a pronoun in both the statement and the question From what we have seen to this point an NP can consist of a proper noun John or a pronoun PRO or a determiner DET and noun N the man or DET N PP prepositional phrase the man in the canoe or DET N S the man who lives upstairs We will call who lives upstairsan S It is also called a relative clause where who is a relative pronoun that in this case has substituted for the subject the man We can now spell out the phrase structure rules that expand the NP 11 NP N PRO DET N DET N PP DET N S Turning to the VP we find it consists of a verb V such as swim V and NP such as drive a truck or even V and S such as think John can swimas in 12 The man who lives upstairs will think John can swim Thus the VP is expanded as follows 13 VP V V NP V S Finally the PP consists of a P preposition such as in to at etc and NP Thus PP is expanded as follows 14 PP P NP We now have a set of PS rules that can generate all the sentences we have looked at so far We only need a lexicon that can insert words for N DET P V to generate additional sentences Rule 10 is an example of a rule that inserts words for the category AUX Derivations A derivation applying the PS rules in the order given would look like the following 15 Example 15 represents a derivation of a sentence by applying PS rules Each line of the derivation represents the application of one rule Self Assessment Exercise 5 Try it yourself Generate a sentence top down by applying the phrase structures rules developed so far If you run into problems bring them up in the discussion session Tree Diagrams and Labeled Bracketing The derivation in 15 can be represented in a tree diagram as follows 16 Or it can be represented by a bracketed string where the brackets are paired and have category labels 17 S NP DET the N man AUX can VP V swim Self Assessment Exercise 5 Try it yourself Create a tree diagram top down by applying the phrase structures rules developed so far If you run into problems bring them up in the discussion session Recursion One very interesting aspect of PS rule 13 is that one of the options for expanding VP is V …