[citation needed] Poplack's work privileges the use of large-scale digitized databases of unreflecting, vernacular speech and variable rule statistical methodology.

Over three decades, she made numerous contributions to the understanding of bilingual syntax in social context, many involving typologically contrasting language pairs.

Much of Poplack's recent work investigates the question of whether the grammatical prescriptions of Standard French are stable, invariant, and consistent.

[8] Poplack's analyses of vernacular varieties of New World Spanish,[9] Canadian French[10] and English,[11] and Brazilian Portuguese[12] are characterized by skepticism towards standard explanations of variation and change based on language simplification or external influences, in favour of historical and comparative studies of internal evolution.

She has won a Fulbright visiting scholar award (1990), a Trudeau Foundation fellowship (2007), the Ontario Premier's Discovery award (2008), a Fellowship with the Linguistic Society of America (2011), the Gold Medal for Achievement in Research (2012) by the Social Sciences and Humanities Research Council of Canada,[16] and the André-Laurendeau Acfas prize (2019).