Questions: Parameter Setting and Universal Grammar

Question 1

A child acquiring Italian correctly omits subject pronouns early in acquisition. According to parameter theory, what else should she know, even without having heard direct evidence for it?

• A. Nothing — each grammatical rule must be learned separately from examples in the input
• B. Properties correlated with the pro-drop setting, such as rich agreement morphology and verb-subject inversion, even without direct exposure to each
• C. That all other languages also allow pro-drop, since it is the universally preferred setting
• D. That English will also allow pro-drop once she learns it, since UG is shared

Answer: (B)

The clustering effect is the core empirical prediction that distinguishes parameter theory from a mere list of language-specific rules. Setting the pro-drop parameter to [+pro-drop] should deliver correct behavior on all grammatical properties that cluster with it — rich agreement morphology, verb-subject inversion in embedded clauses — without requiring direct evidence for each one. If a child needed direct evidence for every correlated property separately, parameter theory would offer no explanatory advantage over item-by-item learning.

Question 2

A linguist proposes that English children acquire the rule against null subjects through explicit parental correction ('You have to say I went, not just went'). How does parameter theory evaluate this proposal?

• A. It supports the theory, since parental correction is the mechanism that sets the parameter
• B. It conflicts with the theory — parameters should be set by positive evidence in the input, not negative feedback, which is known to be rare and often ineffective
• C. It is compatible with the theory as long as inversion is on a separate parameter from pro-drop
• D. It is irrelevant, since parameters are set after acquisition is complete

Answer: (B)

Parameter theory is motivated in part by the poverty of the stimulus: children acquire complex grammatical knowledge that outstrips the evidence available in their input, and explicit correction (negative evidence) is demonstrably rare in child-directed speech and largely unheeded when it occurs. Parameters must be set from positive evidence alone — hearing sentences of a certain type. A proposal requiring explicit correction for every grammatical rule undermines the explanatory point of parameter theory: that innate structure, not piecemeal instruction, accounts for rapid and systematic acquisition.

Question 3

Children learning different languages start with different innate grammars provided by universal grammar, and this is why they end up speaking different languages.

• T. True
• F. False

Answer: False

All children are born with the same UG — the same set of principles and the same inventory of parameter switches, initially unset. What differs across languages is how those switches get set as children are exposed to input. A child acquiring Italian sets the pro-drop switch to [+pro-drop]; a child acquiring English sets it to [-pro-drop]. The languages differ in parameter settings, not in the innate grammar children begin with. UG's universality is precisely the theoretical claim: all children share the same starting point.

Question 4

If the pro-drop parameter is set correctly, a learner should produce correct behavior on correlated grammatical properties — such as verb-subject inversion — even without direct evidence for each.

• T. True
• F. False

Answer: True

This is the clustering effect, the central empirical prediction of parameter theory. Parameters are not just abbreviations for individual rules; they are hypothesized to bundle multiple correlated grammatical properties together. Setting one switch correctly thereby automatically aligns the learner's grammar on all the bundled properties. This explains rapid acquisition: a child doesn't need direct evidence for every property — she only needs enough evidence to identify the correct parameter setting, and the rest follows.

Question 5

Why does parameter theory offer a solution to the poverty of the stimulus problem in language acquisition?

Model answer: The poverty of the stimulus problem asks how children acquire grammatical knowledge that seems to go far beyond the evidence they receive in their input. Parameter theory's answer is that children don't need direct evidence for every grammatical fact. They need only enough input to determine the correct setting for each parameter switch. Once a parameter is set, all the grammatical properties clustered with it follow automatically — from the clustering effect. A child who hears enough sentences to identify that her language is [+pro-drop] thereby gains correct knowledge of all correlated properties, without needing specific evidence for each. The innate parameter inventory, combined with clustering, explains how children acquire so much grammar so quickly from impoverished input.

The key is that parameters compress an enormous amount of grammatical knowledge into a small number of binary choices. If acquiring a language required learning thousands of independent rules from individual examples, acquisition would be slow, error-prone, and dependent on far more input than children actually receive. Parameters reduce the learning task: each setting decision propagates correct knowledge across many properties at once, making the acquisition trajectory compatible with the evidence actually available.