The problem reads:

In F^n, let e_j denote the vector whose jth coordinate is 1 and whose other coordinates are 0. Prove that {e_1, e_2, ... , e_n} generates F^n.

So, we are trying to prove that the span(e_j) = F^2. I am tempted to just pick an arbitrary vector of F^n, but do not really know where to go from there. Help would greatly be appreciated.