• Spanish
• Linguistics
• Second Language Acquisition

Linguists have proposed that language learner behavior does not reflect a single

system, but “is a complex of quite different [linguistic modules] each obeying different

principles” (Sharwood Smith 1994). When different linguistic modules interact in

language, there is an interface. Second language acquisition (SLA) researchers have

proposed the Interface Hypothesis, which states that second language (L2) learners are

able to acquire narrow syntax, but may experience delay with the interface of syntax and

other modules (Sorace & Filiaci 2006). Additional research has proposed that syntaxsemantic

features are acquired sooner than syntax-discourse features in SLA (Tsimpli &

Sorace 2006). One way researchers have tested this hypothesis is by studying L2 learners

of pro-drop languages like Spanish.

Pro-drop languages allow subject pronouns to be expressed overtly, as in the

Spanish phrase Yo veo (I see), or null, as in Veo (*Ø see). Studies show that native

speaker distribution of subject pronouns deals with the interface of narrow syntax and

features of discourse, semantics, etc. Although subject pronouns in Spanish are

grammatically variable (i.e. either a null or overt subject pronoun is grammatically

acceptable in many contexts), the actual distribution of null and overt subject pronouns in

Spanish is predicted by variables such as the person and number of the subject, continuity

of reference (i.e. whether the verb retains the same subject as the previous verb or not),

clause type, and so on.

Previous studies have found that L2 learners of null subject languages learn the

narrow syntax of subject pronouns early (Rothman 2008), but their distribution of subject

pronouns does not become more native-like until a late stage in their development. The

current study analyzes 17 interviews in Spanish with English-speaking L2 learners of

Spanish who have obtained varying degrees of proficiency: beginner, intermediate,

advanced. The results support the Interface Hypothesis given that all interviewees

produced null and overt subject pronouns, but the L2 learners differed greatly from native

speakers with respect to sensitivity to interface features. The results do not confirm that

syntax-semantic features are acquired before syntax-discourse features but do suggest

that syntax-morphology features are acquired before other interface features.