“…Previous studies in adult heritage Russian in the US have reported vulnerability or loss of aspectual distinctions, which they mostly attribute to Attrition over the lifespan (e.g., Polinsky, 2008), the Bottleneck Hypothesis (e.g., Mikhaylova, 2018), and the Interface Hypothesis (e.g., Laleko, 2010). Moreover, studies on heritage Spanish in the US found inaccurate production of aspect, avoidance errors, and low accuracy which they attribute to Attrition and/or Incomplete Acquisition of aspect in Spanish (Cuza et al, 2013;Corbet & Dominguez, 2020;Montrul, 2002;Montrul & Perpiñan, 2011;van Buren, 2012) and an overuse of the perfective form which they attribute to cross-linguistic influence from English.…”