Here's the correct matching for the words and definitions provided:

1. **reach** - **I. goal**
2. **bargain** - **D. a good buy**
3. **multi-linguist** - **F. a person who speaks more than one language**
4. **proficiency** - **E. mastery**
5. **criterion** - **J. standard**
6. **nonnative speaker** - **G. a person who speaks a language which is not his/her first language**
7. **target** - **H. necessary**
8. **authenticity** - **C. genuineness**
9. **credentials** - **B. degrees or other qualifications**
10. **approach** - **A. way of doing something**
11. **clinging** - **X for none (not matched)**

The words "clinging" and "reach" do not have corresponding definitions in the list provided.