Well, you could post a tandem request (first thread in the language corner) and exchange language skills.
If you don't get responses you could as well post at the notice board of the university:
http://www.marktplatz.uzh.ch/lerngruppen/
In which language do you communicate at work? Why are you in the hurry to learn English fast? It's a bit strange if a friendship is solely based on the need to learn English very fast. A bit more information could help. Maybe a tandem learning partner could be the right option and/or hanging out in Irish pubs.
Concerning the short time period, an intensive language course could be necessary.