他误把糖当成了盐放进了汤里。

He was ___mistaking sugar for salt when he added it to the soup.

我把他错认成了我哥哥，因为他们长得太像了。

I ___mistook him for my brother because they look so alike.

我误把盐当糖放了，结果汤变得太咸了。

I ended up ___mistaking salt for sugar, making the soup too salty.