if i understand well ( and even if I did not understand well it helped me a lot) cel - cea - cele correspond to French CELUI - CELLE - CEUX - CELLES - : for instance, this sentence which I did not understand, became very clear when I translated CEL by CELUI and I obtained the following literal translation : MIHAI est celui plus fort homme = Mihai est l'homme le plus fort, in English Mihai is the strongest man. This system works every time CEL CEA CELE appear in a sentence. I hope it will help my fellow French-speaking nationals and students.
Cel and cele are different forms of the same thing, but based on the number and genre of what they are about.
Mihai is a man, so masculine singular for which you have cel. For female singular you have cea. For plurals, you have cei for masculine and cele for feminine.
The whole expression cel mai... means the most... or in cases like this (cel mai puternic) worded a bit differently as the strongest. You can also have ele sunt cele mai mari as they are the biggest.
I got a problem with the position of the adjective. Normally as far as i got it, the order is: noun first and the adjective following up. For example un bărbat puternic, o femeie puternică. When using comperatives the order is vice versa? Would it be wrong to say Mihai e bărbat cel mai puternic? And does Romanian not use the definite article in this case?
In Romanian, determinants that qualify nouns are allowed to swap to the other side of the noun they are qualifying. This is most often used for emphasis, and is apparent in spoken language because it changes the intonation:
bărbat puternic -> puternic bărbat (strong man)
Puternic bărbat ai! - Strong man you got there!
Where the noun carries an article (definite or indefinite, but it is more apparent for the definite), the article is attached to whichever is the first term in the construction:
bărbatul puternic - puternicul bărbat (the strong man)
un bărbat puternic - un puternic bărbat (a strong man), never "puternic un bărbat".
It still designates the noun even at a little distance away, but it is always copulated to the first item of the construction.
In Romanian, the demonstrative pronouns cel/cea/cei/cele, by their nature, are definitely articulated in and of themselves. There is no way to de-articulate them. Often times their direct translation into English is indeed the definite article itself, as in the case of the famous (to Romanians) tale of
"Prâslea cel voinic și merele de aur” ("Prâslea the brawny and the golden apples").
With regard to your question, while it is still incorrect to say
"Mihai este bărbat cel mai puternic”,
it's really a quick fix. Remember how we said before that the article always attaches to the first item in the noun + qualifier construction? In this case, the first word is „bărbat”, and therefore the construction demands a definite article (not an indefinite because the superlative ”cel mai” / "the most" requires a definite article; you can't say "Mihai is a strongest man"). Crucially, this is the case despite "cel" (as we said) already being definitely articulated. So, the sentence we would arrive at is:
„Mihai este bărbatul cel mai puternic.”
However, when we invert the sentence back to the form Duo put it to us, and keeping in mind that „cel” is already articulated, we would get
”Mihai este cel mai puternic bărbat.”
with no apparent definite article, yet indeed with it hidden away in the relative superlative construction (”cel mai” - ”the most”).
Hope this was useful and understandable!
Thanks for your answer in detail concerning my question. Now i know that cel/cea/cei/cele carry the definite article although it is kind of hidden. :-) I was not able to find an answer to my question on the internet so your response was really needed and is indeed so very helpful. Thanks a lot.