I'll say!

You can say “I'll say” to show that you strongly agree with what the other person says. We often use “I'll say” to imply that what the other person said was an understatement, and that the truth is even “stronger” than their statement.

你可以说“I'll say”来表示你强烈同意某人说的话。其中隐含了你认为某人的话较为保守，其实事实程度更深的含义。

A: Wow – that's a big fish.

哇，这鱼真大。

B: I'll say! (implies that the fish is not just big… the fish is GIGANTIC).

可不是嘛!(隐含我认为这条鱼不止是大，简直是巨大。)

A: What a handsome couple they make!

他们真是天生的一对。

B: I'll say.

是啊!我也有同感。