I don't know what is expected by your professors/lecture-persons/tutors but when I think of a language I think of the syntactic properties associated with the language whether that includes some sort of grammar, finite automata description, or markov model (or a combination of the three).
It's just a little hard to know exactly what the question is asking let alone to give an adequate answer.
Do you have another question like this that has an existing solution? Also are doing this as part of a particular course? (Compiler design, linguistics, etc)?