のか　or か or かよ all indicate a degree of questioning and surprise, I think. No worries since it wasn’t intentional. Here’s the WWWJDIC definition so be careful about how you use it.

下らない 【くだらない】(adj-i) (uk) good-for-nothing; stupid; trivial; worthless;

@TorotoroYamaimo
Nice translation!
Ha, you make some very good points. Sounds like you have a very sarcastic wife! I guess I should say there is no sarcastic tone and you really need context to pull it off.

(雨が降ってる時)
A-さん: ああ、いい天気だね

A:あっそー、日本語にサーカズムがま・っ・た・く・ないんだぁ、ふ～ん。
B:まあ、その通りなんだけど。日本語にはサーカズムってのがそもそも存在しないって。
A:ナルホドネ。日本列島にサーカスティックな人が一・人・た・り・と・も・存在しないんだあ。
B:まあ、そう言えるね。
A:で、日・本・人・全・員・と面識を持ってるあんたのことだからこそそう言いきれるねぇ。
B:まあ、そういうわけでもないけど、日本語という言語はその性質上、どちらかというとサーカズムは言い表せない。つまるところはそれを指す言葉でさえ存在しない。
A:そっかぁ、日本語ではサーカズムの概・念・で・さ・え・もまったく表現できないかぁ。
B:まあ、私が考え付くので一番近いのは人の言うことを素直に聞かないで素っ気ない態度をとるときの「はい、はい」ぐらいだ。
A:まあ、日本語のことなら何・で・も・知っているあんただからなぁ、信じるしかないっかぁ。
B:それ、サーカズムのつもりだった？
A:さあな。とくに何の意味もなく適当に傍点をうってしゃべってるつもりだったけど？

You should witness an argument between me and my wife. You’ll find quite quickly that sarcasm is producible and does indeed exist in Japanese… Not exactly something I’m proud of, though. Most common in our arguments is probably “あっそー、ふ～ん”.

Outside of arguments I think the one I get the most might be “すばらしいな、きみ”… No, sorry my wife, I’m simply not ever going to be able to perfectly fold the clothes just as you desire.

As for how sarcasm is referred to in Japanese, it is typically 皮肉. It may also be referred to as 嫌味, and the very definition of your most typical sarcasm could probably be said to be 遠まわしの嫌味. Other words and phrases that may be relevant that I can think of off the top of my head would be 皮肉な調子（口調）, 皮肉を効かした, 皮肉屋, and, my favorite, 皮肉る.

Oh, and in terms of something that’s more so uniquely Japanese, I take it you’ve heard of a ノリツッコミ before, right? Taken as a whole, it can perhaps be taken as sarcasm of a sort.

Also, English-wise, I would note that also long as you’re talking about irony in a general sense, sarcasm can be said to be a subset of irony.

I will, however, note that on a whole, sarcasm seems to be used considerably less in Japanese than in English, at least in my experience. That, I feel, is particularly the case when you get into humor.

@Daniel
Just so you know, くだらない used like you did would be more akin to saying “pathetic” in English.

Ok, fair enough. An honest question though, what exactly does のか　or か or かよ convey if not sarcasm? I don’t really care what we choose to call it, if you don’t want to link it directly to english sarcasm thats cool, but I always get a sarcastic-y vibe from it. Maybe I’m just trying to lump sarcasm and cynicism and all the negative -isms into one ball or something…

And I apologize, I thought くだらない was more along the lines of “silly”, I meant no disrespect or insult. You know you’re my hero :p

The のか doesn’t really convey sarcasm evidenced by the fact that I completely missed that intent in your comment. I guess my point is that there is no sarcastic tone like the one in English that I hate so much. People will always take what you say at face value unless the context obviously indicates the opposite like your example.

By the way, in case you didn’t know saying someone or something is くだらない is very insulting.

@boon-nas & Elliott

嫌味 is perhaps the closest thing Japanese has to sarcasm but I think it comes from malice not like the annoying rolling-eyes sarcasm we have in English. So Elliott, I think your first translation is correct.

それは嫌味で言っている?

So would you guess the translation is

Is that said to upset me?
instead of -
Are you being sarcastic?

Sorry I can’t remember what 電車男 wrote on the forum to prompt this response in the drama. Something like ‘I’m not sure if I’m going to see her again’ this is after all the help they gave him.

言語によって表現出来ないことを考えるのはくだらないと思ってますよ。僕の能力で日本語の説明出来ないので…

I slapped my previous post together just to bring up that I think attaching のか or just か to normal statements is used to express sarcasm. I mean, do you not see/hear this all the time? Maybe it’s not the exact way you express sarcasm in English (although oftentimes I think it is basically the same), but I can’t see how the basic idea of sarcasm can be absent in any given language.

Not to mention I’ve heard sarcasm used on multiple occasions in the exact same way its used in English. Quick example being when I was eating お好み焼き with a friend, and I was eating rather messily (is ‘messily’ a real adverb?) and she made fun of me saying “きれいだよね”. Is that not sarcasm, and is that not exactly how its used in English?

I feel strange questioning the knowledge of someone with far superior skill than me, but I really do think its bizarre to think such a basic human sentiment can’t be expressed within the context of a certain language.

And if you directly translate your original post and add some “かよ” or “のか” here and there does it not make those statements sarcastic?

sarcasm に対応する語……「嫌み／嫌味」が近い意味かも。