This study investigates the contribution of proficiency, length of stay, and intensity of interaction to the recognition and use of conventional expressions in L2 pragmatics by host-environment learners of English. An aural recognition task and an oral production task targeting conventional expressions were completed by 122 learners and 49 native speakers of American English via two computer-delivered tasks: The aural recognition task consisted of 60 conventional and modified expressions, and the oral production task consisted of 32 scenarios pretested to yield conventional expressions (Bardovi-Harlig 2009). Proficiency was determined by scores on a 3.5-hour, four-part placement exam, yielding four low-intermediate to low-advanced levels. Length of stay in the host environment was measured in months. Intensity of interaction was measured by self-report of weekly English language use outside class with native speakers, daily use with other learners, and television viewing. A repeated measures logistic regression model showed significant influence of intensity of interaction on recognition of conventional expressions. A separate repeated measures logistic regression model showed that both proficiency and intensity of interaction have a significant influence in the production of conventional expressions. Length of stay did not have a significant effect on either recognition or production.