Four students of different nationalities are in a dilemma.
Each speak only two of the following languages: French, English, Spanish and Mandarin.
They do not have a common language that they all speak.
Only one language is spoken by more than two students.

Hints    :  - No one speaks French and Spanish.
                 - John does not speak English but can act as interpreter when Pierre and Simon wish
                    to communicate to one another.
                 - Simon speaks Spanish and can converse with Guillaume even though Guillaume does not speak
                   Spanish.
                 - John, Pierre and Guillaume can not converse in the same language.

Question : Which languages does each student speak?

See answer