أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
If you need a general proficiency in a language, including English, then it is the ability to converse effectively.
But if you want to study in a University in an English speaking country then you need a certified proficiency in English speaking, listening, reading and writing. The type of certificate and thedesired score may vary from Uni to Uni and country to country, but a certificate is essential.
Generally IELTS, TOEFL and GRE are being accepted.
Depends on the requirements of each country or entity (University), but in most cases the requirement for nationalities non-English speakers is to have an IELTS examination, TOEFL or similar exams with minimum scores.
You say that you know a language, and you mastered it if you think in that language. So you need to weigh it when we learn a second language.
Talking too much
To my mind and in it's broadest sense: "to understand and to be understood"!
speak as much you can to have experties over any language.
An effective approach to apply the three important elements (talk, listen, and read), don't worry try to talk to everyone in english, listen to the TV (news and business channels), read the english litrature and news magazine, sure you wil improve your english skills, in addition to that attend english courses.
the four basic skills : reading , writing , listening and speaking. whenever you master all those skills , it means that you hve mastered the language
way too broad ,takes a helluva lot