I translated this as 'I am the professional' which was rejected. Duolingo gave either 'I am professional' or 'I am a professional'. I understand that there are no definite articles in Turkish and I also thought that if it were 'I am a professional' it would be 'ben bir profesyonelim'. How therefore would you say 'I am THE professional?'
I'm still not getting it, but thanks for all replies! So, 1) Why not add 'bir' to profesyonelim benim' if you want to say 'I am a professional'? Bir has appeared in all sorts of sentences before! 2) If you don't add 'bir' how do you know whether it's 'I am professional' or I am a professional'? 3) If I want to say 'I am the professional', how do I say that? 4) Profesyonelim olan benim would literally mean 'I am professional which is mine'? (I had to look up 'olan'.). Thanks again for all replies - continue till I'm clear!
It could be both. We don't distinguish adjectives from nouns. The same word can be a noun, an adjective or an adverb.
Yavaş benim tarzım değil. - Slow is not my style. (Yavaş - noun)
Yavaş arabaları sevmem. - I don't like slow cars. (Yavaş - adjective)
Yavaş konuşun. - Speak slowly. (Yavaş - adverb)