What is the title of a public lecturer at foreign university employed to teach native language?

There isn't one single title. The title will vary depending on the university, the country, and the lecturer's seniority and qualifications. Some possibilities include:

* Lecturer in [Language]: This is a common and straightforward title.

* Assistant Professor of [Language]: This implies a higher level of qualification and responsibility.

* Associate Professor of [Language]: Even higher level.

* Professor of [Language]: The highest academic rank.

* Instructor of [Language]: Often used for less senior positions, sometimes part-time.

* Visiting Lecturer/Professor of [Language]: For someone teaching temporarily.

* Language Instructor: A more general title.

The specific language (e.g., "Lecturer in English," "Professor of Spanish") will always be included.