This text focus on research professionals, underlining it is a language career. After a theoretical presentation to remind to which extent language is at the core of this occupation, a section is dedicated to the articulation of published critical typologies of research professionals in France, which illustrate strong internal conflicts. Then, four controversies are presented and analyzed, showing more scientific interactions. Toward the theoretical presentation of the beginning of the chapter, it demonstrates how difficult it is to be aware of such language dimensions when starting a training to become a research professional, while the importance of this very early step may be so important from a language perspective.