てしょうがない/てしかた(が)ない, "You shouldn't"


As far as I know, forms like 「てしょうがない」 and 「てしかた(が)ない」 means something like
"very, extremely" and "can't be helped", like:

> 心配する理由はなかったけど、どうしても不安でしかたなかった: I didn't have any reason to worry, but I
> couldn't help be uneasy

Then I found this sentence:

> そんな本は読んでも仕方がない

which was translated as "You shouldn't read a book like that", while I
translated it as "I can't help reading a book like that"; there is no context,
it's an example sentence from a grammar.

I know those form [can also
mean](https://jisho.org/word/%E4%BB%95%E6%A7%98%E3%81%8C%E7%84%A1%E3%81%84)
"There is no point in doing something", but I'm not sure how to discriminate
between those meanings. After reasearching a bit, I thought the difference was
in the 「も」: 「てしかたがない」, "I can't help but"; 「てもしかたがない」, "I shouldn't". The
again, I just found this sentence:

> こんな酔っぱらいと時間をつぶしたってしょうがない

which to me sounds like "I couldn't help wasting time with such a drunkard",
while it was translated as "I shouldn't have wasted time with such a
drunkard", without having 「も」. I'm wondering if 「たって」 is a colloquial form for
「ても」: I know some time ago I found such a case, but I can't find it anymore.

I found some questions here about these forms, but nothing addressing this; in
my grammar and on the Internet all I can find are the meaning I gave above,
with no explanation about the "You shouldn't" meaning. I did find
[this](https://japanesetest4you.com/flashcard/learn-
jlpt-n2-grammar-%E3%81%A6%E3%81%97%E3%82%87%E3%81%86%E3%81%8C%E3%81%AA%E3%81%84-te-
shou-ga-nai/) page, in which there are examples like
「まだ証明されていないことを考えてみても仕方がないぜ」, translated as "Do not spend thoughts on a matter
which has not been proved", which seems to prove my point, since it does have
「も」.

Am I missing something? Am I right in my `「てしかたがない」, "I can't help but";
「てもしかたがない」, "I shouldn't"` interpretation? Is it just depending on context?




I think you're right. ～てしょうがない/～てしかたない (without も) can mean "(I) can't help
but...", and ～て **も** しょうがない/～て **も** しかたない, "(You) shouldn't..."

And you're also right that ～～たって (<た+とて) is a colloquial way of saying ～～ても,
"even if".

So these phrases are _literally_ like...

  * [感情・感覚を表す表現(phrase expressing feeling or emotion)] + て(で) + しかた(が)ない/しょうがない/しようがない (or たまらない/ならない)  
→ "I want/feel... + and + nothing can be done about _it_ (←the feeling)." → "I
can't help feeling..."

  * ～て **も** /～た **って** + しかた(が)ない/しょうがない/しようがない  
→ "Even if (I/you) do~~, + nothing can be done about _it_ (←the situation)." →
"There's no point in doing..."

Examples:

>   * 心配で仕方なかった。 I couldn't help worrying. / I was really worried.
>   * 心配して **も** 仕方ない。 There's no point in worrying. / Don't worry.
>   * あの本が読みたくてしょうがない。  
>  I can't help but want to read that book. / I wanna read that book so bad.
>   * そんな本、読んだ **って** しょうがないよ。  
>  There's no point in reading a book like that. / You shouldn't read a book
> like that.
>




I think you're right. ～てしょうがない/～てしかたない (without も) can mean "(I) can't help
but...", and ～て **も** しょうがない/～て **も** しかたない, "(You) shouldn't..."

And you're also right that ～～たって (<た+とて) is a colloquial way of saying ～～ても,
"even if".

So these phrases are _literally_ like...

  * [感情・感覚を表す表現(phrase expressing feeling or emotion)] + て(で) + しかた(が)ない/しょうがない/しようがない (or たまらない/ならない)  
→ "I want/feel... + and + nothing can be done about _it_ (←the feeling)." → "I
can't help feeling..."

  * ～て **も** /～た **って** + しかた(が)ない/しょうがない/しようがない  
→ "Even if (I/you) do~~, + nothing can be done about _it_ (←the situation)." →
"There's no point in doing..."

Examples:

>   * 心配で仕方なかった。 I couldn't help worrying. / I was really worried.
>   * 心配して **も** 仕方ない。 There's no point in worrying. / Don't worry.
>   * あの本が読みたくてしょうがない。  
>  I can't help but want to read that book. / I wanna read that book so bad.
>   * そんな本、読んだ **って** しょうがないよ。  
>  There's no point in reading a book like that. / You shouldn't read a book
> like that.
>

