"He is my brother."
Translation:C'est mon frère.
Because that is not the way the French construct such a statement; Please have a look here: http://french.about.com/library/weekly/aa032500.htm
Bonjour! Have a look at the lesson plan (At Work 4). It specifies that we should: A. "Use c’est when you need words like un, ma, etc. before the noun." or B. "use il est or elle est when a noun or an adjective immediately follows." Also, the same question was asked in the current thread 4 years prior to yours, and received extensive explanations. Merci,
It is possible. This exception is motivated by respect or regard, in general. "c'est mon frère" shows a person (with c') and identifies this person as my brother. "Il est mon frère" qualifies "il" as a first name would. I am aware that it is subtle but you can sometimes find this in writing, in biographies, or journalists' reports on people.