Do you say "speak a language at a beginner/ elementary/ intermediate/ advanced level"?
Not a teacher!
I hope I won't give a wrong information but the preposition you are looking for may be "on".
My speaking skill is on an advanced level.
Please correct me when I am wrong.
bhaisahab knows what he is talking about - 'at' is fine.
Incidentally, you may have meant 'please correct me when I am wrong' [that is whenever I am wrong'], but I think you probably mean 'if I am wrong ' - wenn is a faux ami.
b
Perhaps virus would call it a falsch Freund.. . .wenn is a faux ami.
You mean ''die falsche freunde''. Like wir sind die falsche freunde. Am I right Mav? My German gets rusty.
We are getting way off-topic here, but we might as well finish. The expression 'faux ami' or 'false friend' refers to a word in one language that looks like one in another, but means something different, and so misleads us. So, German 'wenn' makes us think of the English 'when', but it it usually means 'if' or 'whenever'.
I don't know whether this expression is used in German, but if it is, as Rover suggested, then, in the sentence ' A false friend can cause problems', it would be 'ein falscher Freund' in German - the words Mav suggested.
However, in the sentence 'Virus would call it a false friend", I believe it should be, "einen falschen Freund" (accusative case). We need to wait for a native speaker of German to confirm whether the expression is used in German at all and, if so, how it would be translated in that sentence.
'die falsche Freunde' (plural) is, think, incorrect; it should be 'falsche Freunde' or 'die falschen Freunde'
Rover's bon mot has got a little out of hand.