"Il est devenu médecin."

Translation: He became a doctor.

[FrenchieRQ]

Why there isn't ''un'' before ''medecin''?

[Sitesurf]

Professions are used as adjectives (without an article) with the verbs "être, devenir, rester". The article comes back when the profession is a noun again, that is when the profession is further qualified.

• He became a doctor = Il est devenu médecin
• He became a famous doctor = Il est devenu un médecin célèbre.

[JoydipChak1]

And that is how French became the toughest language to learn !! Thanks for your explanation though .. as always.