- Problem 3 Context Free Parses Using The Grammar Rules Listed In Section 12 3 Draw Parse Trees For The Following Senten 1 (48.68 KiB) Viewed 39 times
- Problem 3 Context Free Parses Using The Grammar Rules Listed In Section 12 3 Draw Parse Trees For The Following Senten 2 (56.89 KiB) Viewed 39 times
- Problem 3 Context Free Parses Using The Grammar Rules Listed In Section 12 3 Draw Parse Trees For The Following Senten 3 (47.07 KiB) Viewed 39 times
Section 12.3, SPEVEVE STOR examples from the ATIS domain: Some Grammar Rules for English The flight should be eleven a.m. tomorrow The return flight should leave at around seven p.m. I'd like to fly the coach discount class I want a flight from Ontario to Chicago I plan to leave on July first around six thirty in the evening Sentences with imperative structure often begin with a verb phrase, and have no subject. They are called imperative because they are almost always used for commands and suggestions in the ATIS domain they are commands to the system Show the lowest fare Show me the cheapest fare that has lunch Give me Sunday's flights arriving in Las Vegas from New York City List all flights between five and seven p.m. Show me all flights that depart before ten am and have first class fares Please list the flights from Charlotte to Long Beach arriving after lunch time Show me the last flight to leave We can model this sentence structure with another rule for the expansion of S S-VP Sentences with yes-no question structure are often (though not always) used to ask questions (hence the name), and begin with an auxiliary verb, followed by a subject NP, followed by a VP. Here are some examples (note that the third example is not really a question but a command or suggestion, Ch. 23 will discuss the uses of these question forms to perform different pragmatic functions such as asking, requesting, or suggesting) Do any of these flights have stops? Does American's flight eighteen twenty five serve dinner? Can you give me the same information for United? Here's the rule: S Aux NP VP The most complex of the sentence-level structures we will examine are the various wh-structures. These are so named because one of their constituents is a wh-phrase, that is, one that includes a wh-word (who, whose, when, where, what, which have why). These may be broadly grouped into two classes of sentence-level structures, The wh-subject-question structure is identical to the declarative structure, except that the fint noun phrase contains some wh-word. What airlines fly from Burbank to Denver? Which flights depart Burbank after noon and arrive in Deiner by six pm? Whose flights serve breakfast? Which of these flights have the longest layover in Nashville? Here is a rule. Exercise 12.10 discusses rules for the constituents that make up the Wh-NP W.NP VP
12.3 SOME GRAMMAR RULES FOR ENGLISH DECLARATIVE 14. In this section we introduce a few more aspects of the phrase structure of English; for consistency we will continue to focus on sentences from the ATIS domain. Because of space limitations, our discussion will necessarily be limited to highlights. Readers are strongly advised to consult a good reference grammar of English, such as Huddleston and Pullum (2002). 12.3.1 Sentence-Level Constructions In the small grammar Lo, we provided only one sentence-level construction for declar- ative sentences like I prefer a morning flight. There are a large number of constructions for English sentences, but four are particularly common and important: declarative structure, imperative structure, yes-no-question structure, and wh-question structure. Sentences with declarative structure have a subject noun phrase followed by a verb phrase, like "I prefer a morning flight". Sentences with this structure have a great number of different uses that we will follow up on in Ch. 23. Here are a number of examples from the ATIS domain: