兩種情形看起來有些相似，但實質卻有很大區別——這種情況我們在日常生活中偶爾會遇到。用英語應該如何表達？

1. There's a fine line between drinking socially and alcoholism.
喝酒應酬和嗜酒可是有區別的。

2. There's a fine line between helping your kids with their homework and doing it for them.
幫孩子做作業和替孩子做作業可是有區別的。

3. There's a fine line between dressing a little sexy and looking trashy.
穿著性感和穿得很low可是有區別的。

4. There's a thin line between courage and foolishness.
勇敢和魯莽可是有區別的。

總結

如果說A與B之間有個fine line，那么就表示：雖然A與B很相像，但其實有很大區別，而且通常情況下，A比B要好。這里的fine line也可以說成thin line。不過，“A好B壞”這種分法也不是絕對的。比如下面這兩個例子：

As a ?parent, I ?knew that there was a fine ?line between ?panic and ?caution.
作為一位家長，我知道嚇唬孩子和提醒他們還是有區別的。

It's a fine line between being a backseat driver and a considerate passenger.
坐在后座的情況下，指手畫腳和好心提醒還是有區別的。

（中國日報網英語點津 杜娟）