Did Hiddink speak fluent Korean when he took South Korea to the World Cup semifinals? Or Russian while he was Russia's manager.
Since when were Korea and Russia top European club sides? You do realise that managing an international team is very different from managing a league side. For a start you are only with the players for 8-10 long weekends each year, and then perhaps 4-6 weeks every 2-4 years (for a tournament). You don't really develop the players as much as a club manager, you have less matches, less press conferences, less interaction with your players.
Did Terry Venables speak fluent Catalan or Spanish when he won La Liga with Barca?
Apparently he does speak Catalan:
http://www.independent.co.uk/voices...bles-is-in-a-different-ball-game-1453121.html
It's not really necessary to be
totally fluent in a language, but I think you would definately need a working knowledge of it. When Bobby Robson spoke Portguese at Porto interviews and conferences, it wasnt word-for-word perfect, but it was good enough to be understood.
http://www.youtube.com/all_comments?v=OP8F1RD5y78
Obviously you will get some managers who are able to speak the language but are not sucessfull for other reasons (Platt can speak reasonable Italian but wasnt that great as Samp coach - there were issues at the time with him not having Italian coaching badges so not being an official coach; Christian Gross was a disaster at Spurs despite speaking fairly good English). If you look at a lot of sucessful foreign managers in the big European leagues, they all tend to have a working knowledge of the domestic league. Ancelotti, Mancini, Mourinho, Wenger all spoke English - that's all the foreign winning coaches who have won the PL. Benitez and Di Matteo (the two coaches who've not won the PL but have won the CL with English teams) also spoke English.
In Spain various foreign coaches like Mourinho, Hiddink, Heyenkes, Schuster, Antic have all spoken Spanish. In the history of Italian football, while there havent been that many foreign coaches, most (maybe all) of the ones who have won titles (Ericksson, Herera, Mourinho) have spoken Italian and even ones who havent won major titles have usually spoken it (Zeman, Hodgson).
I cant think of that many sucessfull (or more than 1 season) foreign coaches in Germany apart from the ex-Bayern ones I mentioned (and you have to exclude Austrians and Swiss like Happel, Kurt Jara and Lucien Favre since German is the prevalent language in those countries). But ones like Huub Stevens, Arie Haan, ,Mulder and Wilmots (Belgians at Schalke) have all spoken passable German. As well as Jol, HSV had a few non-German caretakers in these last few years, Cardozo, Moniz and Arnesen - again all of these guys spoke reasonable German.