In the sentence 'The ice melted,' what thematic role does 'the ice' bear, and why is this theoretically significant?
AAgent — because it is the grammatical subject and subjects are always Agents
BPatient/Theme — the ice undergoes the change of state without intentionally causing it, demonstrating that grammatical subjects need not be Agents
CInstrument — because ice is a physical substance involved in a process
DExperiencer — because the ice 'experiences' a temperature change
Unaccusative verbs like 'melt' and 'arrive' take a Patient/Theme as their surface subject. The subject position is syntactically defined (it controls agreement, determines word order), but it does not fix thematic role. This is exactly what the Theta Criterion captures: each argument gets one theta role, but the mapping between syntactic positions and thematic roles is not one-to-one — it is mediated by the verb's argument structure.
Question 2 True / False
The Theta Criterion states that a single theta role can be assigned to multiple arguments in one clause, as long as each argument receives at least one role.
TTrue
FFalse
Answer: False
The Theta Criterion is a biconditional constraint: each argument must receive exactly one theta role AND each theta role must be assigned to exactly one argument. The 'multiple arguments sharing a role' reading is precisely what the criterion prohibits. This bidirectionality ensures a one-to-one correspondence between semantic participants and syntactic arguments within a clause.
Question 3 Short Answer
What does 'valency' describe, and how does the causative-inchoative alternation ('The vase broke' / 'She broke the vase') illustrate that valency can change?
Think about your answer, then reveal below.
Model answer: Valency describes how many arguments a verb requires: intransitive verbs have valency 1, transitive verbs valency 2, ditransitive verbs valency 3. In 'The vase broke,' 'break' is intransitive (valency 1) with only the Theme argument. In 'She broke the vase,' it is transitive (valency 2) with an Agent added. The same verb participates in both frames, showing valency is not a fixed lexical property but can be altered by argument-structure operations that add or remove participants while preserving the core semantic relation.
The causative alternation is cross-linguistically common and reveals that verbs encode not just an event type but a range of possible participant configurations. Understanding valency as flexible rather than fixed is essential for analyzing passives, applicatives, and other constructions that systematically manipulate argument structure.