How does this meaning of 笑えないかな work?


In [this](http://www.youtube.com/watch?v=QJaareN2z00&feature=player_embedded)
Bump of Chicken song, the line 笑えないかな is used a number of times.

For example:

> 全て受け止めて笑えないかな
>
> If only I could just accept everything and smile.
>
> 誰かに優しく出来ないかな 全て受け止めて笑えないかな
>
> If only I could be kind to someone. If only I could accept everything and
> laugh.
>
> 笑えないかな
>
> If only I could laugh.

The translations are a combination of those provided online, my native speaker
friends and mine. If I translate 笑えない literally I come up with "I can't
laugh." With 笑えないかな, I get "Can't I laugh?" So how does "Can't I laugh?"
become "If only I could laugh." I see the correlation in meaning but I am not
100% there in understanding it. I guess verbない + かな has this nuance of "If
only.."

The more literal way of saying this phrase would be ”笑えたらいいのになぁ” "If only I
could laugh." But how does this colloquial version work?




`か` makes a question, but it does not make a tag question as you thought. And
in this case, it can be interpreted as a rhetorical question.

> 笑えない  
>  'I can't laugh.'
>
> 笑えないか  
>  'Can't I laugh?' (Rhetorical question with the expectation: 'I can laugh.')  
>  → 'I expect/wish that I can laugh'.

The expectation that follows from the question is the opposite of how you
translated. I don't know where your idea of translating it into a tag question
came from.

