Syntex How Do We Find Constituents in a Sentence

Constituents Functioning as a unit… ! The students did their syntax assignment. The students did the crossword puzzle. ! John did the crossword puzzle. ! The crossword puzzle is what John did. ! *Crossword puzzle is what John did the. ! John likes the crossword puzzle. ! John likes the jigsaw puzzle. ! John likes the theater. ! ! Syntax I Finding constituents ! ! ! How do we find constituents in a sentence? For many of them, we can guess, but a guess isn’t evidence. The structure of a sentence has consequences. To find the constituents (to determine the structure) we test for the consequences. Replacement test ! ! A constituent is a group of words which function as a unit. If you can replace part of the sentence with another constituent (the smallest constituent being a single word), this tells us that the replaced section of the sentence is a constituent. This isn’t foolproof, but it usually works if you try to keep the meaning as close as possible. Replacement test ! ! ! The students left. They left. Sentence fragment test ! The students is a constituent. ! ! ! ! The students will eat the sandwiches. They will eat the sandwiches. The students will eat them. The students will dine. Generally, only constituents can be used in the fragmentary response to a question. ! Who will eat the sandwiches? ! What will the students do? ! What will the students eat? ! ! ! ! [The students] will [eat [the sandwiches]]. ! The students. Eat the sandwiches. *Students will eat the. *Eat the. The sandwiches. [The students] will [eat [the sandwiches]]. 1 Ellipsis test ! If you can elide a string, it qualifies as a constituent. ! ! ! ! Movement (topicalization) test ! Ellipsis is really deletion of a string from a sentence. Sometimes this is “repaired” by using the verb do, something which we will seek to explain at a later point. The professors will eat the sandwiches, and then.. The students will. But: ! ! ! ! ! The students will eat the cookies, and then… *The professors will sandwiches. ! Sometimes you can “move” a string of words to the front of a sentence (then generally interpreted as the topic of the sentence). When you can, you’ve found a constituent. ! ! WARNING: Passing a constituency test constitutes evidence for a constituent. Failing a constituency test tells you little—there may be other reasons for the ungrammaticality. The sandwiches, the students will eat _. Eat the sandwiches, the students will _. The students, they will eat the sandwiches. *Students will, the eat the sandwiches. *Students, the will eat the sandwiches ! Again, failing a constituency test isn’t evidence against constituency! Clefting test ! Like the movement test, if you can fit your string into the frame it be X that S (where you move the string X from inside S), X is a constituent. ! ! ! ! ! It’s the sandwiches that the students will eat _. It’s the students that _ will eat the sandwiches. It’s eat the sandwiches that the students will (do) _. *It’s students eat that the _ will the sandwiches. *It’s eat the that the students will _ sandwiches. Finding constituents ! ! Tests: Replacement, ellipsis, movement, clefting, fragment. Some to try: Two African swallows can carry a coconut. A cat was walking down the street. ! A creature was stirring up trouble. ! Flying planes can be dangerous. ! ! And all through the house… Trees, hierarchy, and constituency ! [The students] [ate [the sandwiches]] square bracket notation the students ate the sandwiches tree structure 2 Trees, hierarchy, and constituency ! [The students] [ate [the sandwiches]] the students Trees, hierarchy, and constituency ! ate [The students] [ate [the sandwiches]] the the students ate sandwiches the sandwiches constituent constituent constituent The triangle ! Sometimes, when the internal constituency is unknown or unimportant to the current discussion, a triangle is used instead. Trees ! A B C ! D the students E ! ate the sandwiches Trees ! A B C ! D Nodes with no branches beneath them are called terminal nodes. B, D, E are terminal nodes. E ! ! Nodes with branches beneath them are called nonterminal nodes. A, C are nonterminal nodes. The “joints” of the tree are nodes. The nodes here are labeled (with node labels). Nodes are connected by branches. The node at the top of the tree (with no branches above it) is called the root node. A is the root node. Tree relations ! A B D C D C E E ! A node X dominates nodes below it on the tree; these are the nodes which would be pulled along if you grabbed the node X and pulled it off of the page. C dominates D and E. 3 Tree relations ! A B C D D C E E Remind you of anything? To briefly reconnect with actual language data, it seems as if you do something to C (like pull it off the page), it affects D and E as a unit. Tree relations ! A B D C D C E E ! ! Tree relations ! A B C D E ! ! A node X immediately dominates a node Y if X dominates Y and is connected by only one branch. A immediately dominates B and C. A is also sometimes called the mother of B and C. Tree relations One of the ways we know a verb is a verb (category) is by observing that it can substitute for other verbs. ! ! ! ! ! ! ! Pat likes to sing. Pat likes to drive. Pat bought a book. *Pat bought (a) sing. Pat likes to eat sandwiches. *Pat unpleasant to eat sandwiches. So is eat sandwiches a verb? Well, kind of, yes. It’s a constituent, a phrase, that has the properties a verb does. A verb phrase. ! A B C D E ! ! ! Substitution ! A set of terminal nodes is a constituent if they are all dominated by the same node and no other terminal nodes are dominated by that node. “D E” is a constituent. “B D” is not. A node which shares the same mother as a node X is sometimes called the sister of X. B is the sister of C. C is the sister of B. D is the sister of E. The making of a phrase ! ! ! We’re trying to characterize our knowledge of syntactic structure. Our grammatical knowledge is a system (we can judge new sentences). All things being equal, a theory in which the system is simpler (needed fewer assumptions) is to be preferred over a theory that entails more complex one. 4 The making of a phrase ! ! ! In that spirit, we know that a phrase differs from a word in that it contains words (or other phrases). We’ve seen that when words are combined into a phrase, the phrase inherits the properties of one of the things we combined. (The phrase has a head). Suppose: a phrase can arise from merging two words together, with one taking priority. In a way, attaching one word to another. The making of a phrase ! What will Pat do? ! ! ! What does Pat like? ! ! ! ! sing eat sandwiches to eat sandwiches to sing [to [eat sandwiches]] So, a phrase can also arise from combining to and a verb phrase, to make a bigger phrase. Merge ! ! ! Merge, in the abstract So, let’s go for the simplest theory of structure we can (and only move away from it if the simplest theory won’t work). A phrase is a syntactic object formed by combining (merging) two syntactic objects, with the properties inherited from one of them (the head of the phrase). A word is a syntactic object. ! B D Merge, in the abstract ! ! B C ! D E ! We combine D and E using Merge to form a combined syntactic object. We need to call our new object something, so we call it C. C is now a syntactic object (containing D & E). D and E are now “off the table”—we can’t Merge D with anything because it’s inside C. (“Merge only combines objects at their root nodes”). E ! A good way to think about this is that we have a number of syntactic objects lying around on a workbench of sorts. We use the operation Merge to assemble them together into one syntactic object. Merge, in the abstract ! A B C D E ! Since C is now a syntactic object, we can combine C with the other syntactic object, B, to form a new syntactic object we’ll call A. Now, all we’re left with is the single syntactic object A. 5 Merge, in the abstract ! A B ! C D E When two objects are Merged, one of them is the head, the most important one. The head determines the properties of the constituent— that is, the features of the head project to become the features of the whole combined object. Trees and constituency ! ! Pat will eat lunch. Pat will dine. ? eat [V] lunch [N] So how do we know which is the head? ! ! When we Merge two things, one is the head, and determines the properties of the resulting syntactic object. The next thing we’ll turn to is the question of how the syntactic system knows which is the head. 6