I wonder what I would have done if I hadn't found my smartphone here.
I don't know what I would have done if I hadn't been able to find my phone here.
ーI wonder what I would have done if I hadn't found my smartphone here.
「ここでスマホを見つけられなかったら、どうしようかと思った」
I wonder what I would have done if I hadn't ... で「もし…だったならどうしようかと思った」
ーI don't know what I would have done if I hadn't been able to find my phone here.
「ここでスマホを見つけることができなかったら、どうすれば良いかわからなかった」
I don't know what I would have done if I hadn't ... で「もし…だったなら、どうすれば良いかわからなかった」
ご参考まで！
カナダ 
