A student says: 'In Spanish, speakers can just leave out the subject pronoun when it's obvious — the subject position is simply empty.' What is the technically accurate syntactic description?
AThe student is correct: the specifier of TP is genuinely empty in pro-drop languages — that is what 'null subject' means
BThe subject position is occupied by a covert pronominal element (pro) licensed by verb agreement morphology — the position is structurally filled, just not phonologically pronounced
CSpanish speakers optionally move the overt subject to a topic position, leaving the specifier of TP empty as a side effect
DAgreement morphology on the verb substitutes for a subject argument entirely, so no subject position exists in pro-drop clauses
The common misconception is that pro-drop means the subject slot is absent or empty. In fact, pro is a covert pronominal element that occupies the specifier of TP exactly as an overt pronoun would — it participates in binding, agreement, and case licensing just like 'he' or 'she.' The structural position is present; only the phonological realization is suppressed. This matters syntactically: *Juan dice que pro habla mucho* allows pro to refer to Juan just as an overt pronoun in the same position would, showing that pro is a genuine syntactic object, not an absence.
Question 2 Multiple Choice
Which property of the verb is most critical for licensing a null subject (pro) in a canonical pro-drop language like Spanish or Italian?
ALexical semantics — verbs of mental state and perception more readily permit null subjects across languages
BRich agreement morphology that identifies the person and number of the referent, satisfying the licensing requirement that the empty category imposes
CThe absence of a complementizer in the clause, which would otherwise force an overt subject
DThe availability of a discourse-linked antecedent in the immediately preceding sentence
The agreement morphology on the verb is what licenses pro in standard accounts. In Spanish, *habla* uniquely identifies third-person singular; the rich paradigm across persons means the referent of the covert pronoun is recoverable from the morphology alone. English lacks this richness — 'speaks' is compatible with third-person singular but much of the paradigm overlaps — which is part of why English requires an overt subject. Discourse context plays a secondary role, especially for third-person subjects, but morphological licensing is the structural condition.
Question 3 True / False
In pro-drop languages, the null element pro occupies the specifier of TP and participates in binding and agreement exactly as an overt pronoun would — it is not syntactic absence but a covert pronominal element.
TTrue
FFalse
Answer: True
This is the key theoretical claim that distinguishes the pro-drop analysis from a simple 'omission' account. Pro is a pronominal element with the same syntactic distribution as an overt pronoun — it must be licensed, it can serve as an antecedent and a target in binding relations, and it bears phi-features (person, number, gender) that participate in agreement with the verb. Its only difference from an overt pronoun is that it has no phonological content.
Question 4 True / False
In pro-drop languages like Spanish, speakers can omit the subject pronoun freely in any sentence type and discourse context.
TTrue
FFalse
Answer: False
The pro-drop parameter describes a general structural permission, not an unconditional license. Even [+pro-drop] languages have licensing conditions — the null subject must be recoverable, typically through rich agreement morphology, and there are discourse contexts (particularly with third-person subjects where reference could be ambiguous) where an overt subject is preferred or required for clarity. Additionally, some [-pro-drop] languages allow limited null subjects in specific discourse contexts (diary sentences, lists). The parameter captures a systematic tendency with structural conditions, not a blanket rule.
Question 5 Short Answer
Why is the clustering of properties in pro-drop languages — null subjects, subject-verb inversion in declaratives, free inversion in embedded clauses — theoretically significant for syntactic theory?
Think about your answer, then reveal below.
Model answer: These properties cluster non-accidentally: they are all surface reflexes of a single underlying configuration — how agreement and subject-hood interact in the grammar of these languages. This clustering is exactly what a parameter in the sense of Universal Grammar should predict: a single binary setting (how rich agreement licenses null elements and how subject position relates to the verb) that has multiple, apparently independent surface consequences. If the clustering were accidental, we would expect to find languages with any combination of these properties, but we don't. Explaining why they cluster — and whether they truly derive from one underlying mechanism or from correlated but independent properties — is a central open problem in syntactic theory.
This is why pro-drop is a central test case for parametric theory. If a parameter is a single switch with multiple correlated surface effects, then the pro-drop cluster is strong evidence for the parametric model of UG. If the properties turn out to be independently settable across languages, that challenges the binary parameter account and suggests a more gradient or modular approach.