Frnech -> French
a space after ,

no reply since May 18th 2013, i changed it

I think it should be changed to: "Tom speaks perfect French, but his native language is German."

+1

I would vote for "but". The only way I can imagine that the utterance "Tom speaks perfect French, and his native language is German" would make sense would be in response to a sentence such as "Does anyone here speak French and German?" By contrast, "Tom speaks perfect French, but his native language is German" could stand alone. I'd say that the "but" here expresses not contradiction but surprise: one cannot take for granted that someone who speaks perfect French is a native German speaker (or the inverse: one cannot take for granted that someone whose native language is German speaks perfect French).

@change

I don't know the linked language, but the following English sounds good, if either matches.

Tom speaks perfect French, but his native language is German.
Tom speaks perfect French even though his native language is German.

Changed to "but", using the German (which is older than the Turkish and directly linked to it) as a guide.