The article aims to conduct the experimental research of the adult learners' readiness to learn English, investigate adult learners' barriers to study English and develop the model of English teaching environment for adult learners within university extracurricular activity based on the collaborative teaching strategy. The hypothesis of the research is that motivation to study the English language among adult learners will be increased after the investigation of their learning barriers and work on their minimisation in the conditions of university extracurricular work within the collaborative learning strategy. In order to achieve the purpose of the research, a set of scientific methods was used: analysis, synthesis, complex analytical method, conceptual system method, factual method, descriptive method, questioning, testing, observing, interviewing and generalisation. Respondents were 52 adult learners (age range was from 40 to 55) who were the participants of the Ukraine-Norway project, who attended the course "English for Business". The respondents were united into three age groups: 40-45 years; 45-50 years; 50-55 years. The majority of respondents (51%) showed a high level of a readiness to continue the English study process after completing the proposed course. The application of the suggested in the article model will minimise adult learners' barriers to study English, increase the level of adult learners' motivation to learn English, create a positive learning environment, engage adult learners into the English study process as active participants, promote collaboration and support within the peers.