Translation:The one running fast is my brother.
"Cel care" should be accepted as correct! According to Romanian grammars, there is no significant difference, the two structures "cel ce" and "cel care" can be used in identical contexts and have identical meaning. However, NB: in the feminine singular nominative and accusative, ONLY "cea care" can be used (not "cea ce").
"Cel ce / cel care a prezentat lucrarea despre verb nu este de la universitatea noastră". (The one (masc.) who presented the paper on the verb is not from our university.")
"Cea care a prezentat lucrarea despre verb nu este de la universitatea noastră." (The one (fem.) who presented the paper on the verb is not from our university.)
"Cei ce / cei care au prezentat lucrarea despre verb nu sunt de la universitatea noastră." (The ones (masc. pl.) who presented the paper on the verb are not from our university.)
"Cele ce / cele care au prezentat lucrarea despre verb nu sunt de la universitatea noastră". (The ones (fem. pl.) who presented the paper on the verb are not from our university.)
I hope this helps!
Even though " fuge " and " aleargă" are translated in English with" runs", in Romanian there is a little difference. " aleargă" = he/ she/ they run(s) ( ex: in a race or training) like in our sentence here " Cel care alearga rapid( I would say " repede" instead) este fratele meu". If we replace " alearga" with " fuge" then we would instantly become a bit worried and ask" why?= de ce?"... The vb " a fugii" is usually used ehen somebody has a motive, a reason to run...if something bad happened "fugi de aici= go away from here"( when something dangerous), in case of an accident or if somebody is in need of medical attention " fugi repede la doctor= run fast to the doctor", or when somebody runs away from home " Ion a fugit de acasă= John ran away from home"... if a crime happens " a fugit cu geanta mea= he/she ran( away )with my bag"...and also in the idiom" fuge de mănâncă pământul" = " runs like hell" ...etc.
That would be the norm...but, because Romanian is such a vast language with a lot of words having subtle meanings...please do not get scared if you go in Romania and hear a lot of kids using the vb " a fugii" instead of " a alerga" ...the kids like to use simple, short words...also some people in rural areas do so. :)