My research interests lie at the intersection of two core attributes of human language: (1) its inherent variability and (2) its social nature. The first of these refers to the fact that no two utterances are exactly alike, and also that we have many ways of linguistically formulating similar thoughts and communicating comparable messages. The second attribute arises naturally from the fact that people use language in specific temporal, physical, and social contexts.

Most of my research has focused on variation in the linguistic behavior of Spanish speakers in the United States. In the context of working with this community, I (along with collaborators) have examined numerous variable phenomena in pursuit of answers to a range of questions. Among the findings that have emerged from my research are the following:

• Lenition of Spanish syllable-final /s/ is best viewed as a phenomenon with both categorical and gradient properties (Erker 2010 and 2012, Erker and Reffel 2021, please see my curriculum vitae  for full citation information).
• Patterns of morphosyntactic variation in Spanish are sensitive to lexical frequency effects (Erker and Guy 2012).
• Children gradually acquire sensitivity to linguistic factors that condition morphosyntactic variation (Shin and Erker 2015).
• Intergenerational outcomes of language and dialectal contact among Spanish-speaking residents of New York City include (i) structural convergence, (ii) dialectal leveling , and (iii) intergenerational stability  in variable linguistic behavior (Erker and Otheguy 2016; Erker, Ho-Fernández, Otheguy, and Shin 2017, Erker and Otheguy 2021).
• In situations of linguistic contact, the intergenerational trajectory of patterned linguistic variation is modulated by the varying social salience of specific linguistic features (Erker 2017a).
• Outside the domain of variation in Spanish, my research has also challenged conventional wisdom on the phenomenon of hiatus resolution in American English (Davidson and Erker 2014).
• At present, my primary research agenda is creating a sociolinguistic profile of the Spanish-speaking community in the Greater Boston Area.