monolingually

/ˌmɑnəˈlɪŋɡwəli/
adverb
  1. In a way that involves using or speaking only one language.
    • She grew up monolingually, speaking only Spanish at home.
    • The conference was conducted monolingually, with no translation services.
    • He learned to read monolingually before ever attempting a second language.