Since “spontaneous verbal expression is not solely a product of knowledge and skill in using a language code” (Rivers 1968: 192), many scholars have emphasised the interdisciplinarity of the ability to speak. Having stressed the multifaceted character of speaking in the light of the selected linguistic and non-linguistic determinants of speech, we aim to explore Polish learners’ opinions on what components underlying a speech production process influence their ability to speak English. The quantitative study that we conducted among the group of 66 Polish EFL secondary school and university students revealed that out of 12 linguistic and non-linguistic determinants of speech, the knowledge of FL vocabulary and culture were respectively judge...