Well my mother tongue is German, in school I learned English, French and Latin, during my university studies in addition I learned some Dutch. And I am a native Frisian and so also speak Frisian.
Some of my relatives live in Spain so that I learned over the years a few sentences and with French and Latin I already can read a lot of Spanish, so probably the next language will be Spanish.
But I am also interested in exotic languages like Hebrew and Arab. These languages use totally different letters and write from right to the left.
I think it is good in business to know many languages.