The reason why we use english in XDA:
It's a "common ground" so that EVERYONE can understand. Either those who helps and those who get helped.
And understanding or being understood isn't just about the TS getting it's problem fixed, but also that if ANYONE who has the same issue will have a reference, a place where he can found what is already done to troubleshoot his issue.
I honnestly think that anyone who start a thread in a language that is not understood by all the XDAers is only showing a lack of respect for the others...