We would if we were taught to put the fish back when we were young.这一句中

其实would if应该是分开的,只不过是would后面还有谓语动词,省略了而已,即
Would would do it well if we were taught to put the fish back when we were young.
翻译：当我们小的时候,有人教我们把鱼放回去,我们会做好的.
有不明白的请继续追问,