Is there any difference between 'He doesn't know any foreigin languages other than English.' and 'He doesn't know any foreign languages except English.'?
I'd say there is a difference and the second phrase is right. Its a statement, so its saying he doesn't know any foreign language, except English - so its an exception to the statement. The first phrase is making the statement that he doesn't know any foreign langauges, but then it contradicts that by saying - other than English, so therefore he does. I hope this makes sense, I could be wrong, but I was told that by an English teacher when I was at school. Hope it helps! :)
Believe me, there is no difference in meaning at all. I did not learn this from an English teacher when I was at school...I was, for 40 years, an English teacher!
There may not be any difference in the meaning but, assuming the speaker is English, both phrases are confusing to me. Surely if you're English, the English language is not foreign to you? Should therefore the 'foreign' or 'other than English/except English' not be omitted from both statements?
I thought along the same lines as you initially, Wildwood, but then decided that there was no reason why 'he' should not refer to a Serb, a Senegalese or a Sioux. In any such case, the sentences are perfectly valid.