Just a comment about the translation. “It’s not my cup of tea” has a somewhat different nuance than the French translation; “it’s not my specialty.” The cup of tea sentence has more to do with personal preference, liking, or taste. It also has a much different level of formality. The cup of tea remark is very informal. If my boss asked me to do something, I could reply, “It’s not my specialty.” I might get fired if I said, “It’s not my cup of tea.” Speaking here from Midwest USA, I’m not an expert on British English or otherwise.
As a Briton, my use of this phrase is the same as yours, i.e. it always refers to preference, liking or taste, so I would say that British English and American English have the same usage.
Whilst I have never heard it used to refer to a speciality, the Wiktionary page does suggest this as a possibility, but provides no quotations or similar to justify or demonstrate this - someone’s cup of tea - Wiktionary, the free dictionary
I’m seeing the mistakes in Tatoeba repeated in Reverso.net. I wonder where Wiktionary is getting its information?
Anyway, i thought a lot about it. If “cup of tea” were used in regard to a skill, the implication would be that it was a good fit for that person or made them happy. Not just that they were good at it.
There are definitely things that I am good at that I prefer not to do, and no one would call it my cup of tea unless it was a massive joke. Thank you for the reply and the discussion.
Edit: I should add that I know that Wikipedia is edited by users/ readers. I have edited articles myself. Still, whoever put that in got it from somewhere. There are no citations in that article.
I’m not a French speaker (i.e. native or similar), but I have often used the phrase “Ce n’est pas mon truc” to convey the same idea as “It’s not my thing / it’s not my cup of tea / Das ist nicht mein Ding etc.”
Searching for “mon truc” on Tatoeba brings up the following list, which includes English translations related to “cup of tea” - Sentences with: mon truc - Tatoeba
That’s how I use it too. (never to talk about my skills or lack thereof in a specific domain), so I don’t think the French translation is very good here.
Agreed, I think that “Ce n’est pas mon truc.” would be a better translation.
You could also translate it literally:
“Ce n’est pas ma tasse de thé.” means the same thing in French as it does in English.
It’s not very common though, maybe even considered old-fashioned at this point.