What counts as proficient language?

Related questions

1. What are examples of boundaries?
2. What is the synonym of fluent?
3. What is the synonym of shrewd?
4. What is the difference between effortful and automatic processing?
5. Has difficulty in doing?
6. What is the synonym of venture?
7. What is the synonym of fast?
8. What is the synonym of rare?
9. Is effortful a word?
10. Can you have two native languages?

Tags

1. #speakers
2. #fluency
3. #conversational
4. #basic
5. #without
6. #language
7. #might
8. #little
9. #being
10. #level
11. #words
12. #considered
13. #estimated
14. #proficient
15. #native
16. #between
17. #require
18. #fluent