The explanation lies in the two different ways that "fruit" is defined. First, it is true that scientifically speaking, tomatoes are fruits.

对“fruit（水果，果实）”的定义有两种不同说法。首先，从科学角度讲，番茄的确属于果实。

According to Merriam-Webster, a fruit is "the usually edible reproductive body of a seed plant." In a blog post, the dictionary explained it in simpler terms: "Any thing that grows on a plant and is the means by which that plant gets its seeds out into the world is a fruit."

根据《韦氏词典》，果实通常指“种子植物的可食用繁殖体”。《韦氏词典》博客上的一篇文章给出了更简单的释义：“果实是长在植物上、能够将植物种子带到外面的部分。”

That definition includes apples, tomatoes, and anything else that grows from a plant and contains seeds. (Cucumbers, peppers, pumpkins, and avocados are all fruits too, according to science.)

这个定义包含了苹果、番茄等任何有种子的植物部位。从科学意义上讲，黄瓜、辣椒、南瓜、牛油果都属于果实。

Vegetables, on the other hand, have a slightly murkier definition. It's a word we use to group together a wide range of plants whose parts are edible and herbaceous, like roots, stems, and leaves. The critical distinction is that, according to the dictionary, a vegetable must be part of a plant or the whole plant itself, while fruits are just the means by which certain plants spread their seeds.

另一方面，蔬菜的定义要更模糊一些。我们把一大批具有根茎叶等可食草本部分的植物归类为蔬菜。根据《韦氏词典》，二者的关键区别是：蔬菜必须是植物的一部分或整体本身，而果实只是特定植物传播种子的方式。

"The thing a tomato plant produces isn't a part of the plant itself, any more than the egg a chicken lays is part of the chicken, or the apple is part of the tree on which it grew," Merriam-Webster wrote.

《韦氏词典》称：“番茄不是植物本身的一部分，最多就像蛋与鸡、苹果与苹果树的关系一样。”

But the confusion arises because "vegetable" isn't a botanical classification so much as it is a culinary one. And "fruit" can be a culinary term, too — described as "having a sweet pulp associated with the seed" and "used chiefly in a dessert or sweet course," according to Merriam-Webster. So scientifically, fruits don't have to be sweet, but in the kitchen, most people would classify the fruits that fall on the savory side, like tomatoes, as vegetables.

但问题在于：“蔬菜”更多是一种烹饪分类，而不是一种植物学分类。与此同时，《韦氏词典》称，“fruit”也可以是一种烹饪食材，指“拥有带种子的甜果肉”、“主要用于甜点或甜食”的东西。也就是说，从科学角度，果实不必是甜的；但从烹饪角度，大多数人会根据果实的味道将其归类为蔬菜，比如番茄。

Nutritionists recognize the terms as they are commonly used, and tomatoes are listed as a vegetable under USDA guidelines.

营养学家根据番茄的主要用途将其列为蔬菜，而美国农业部的指导方针也将番茄列为蔬菜。

Even the Supreme Court has weighed in on the issue.

甚至连美国最高法院都曾介入过这个问题。

1883年3月3日，美国颁布了新的关税法，规定进口蔬菜需要缴纳10%的关税，而进口水果则不需要。当时纽约海关认为番茄是蔬菜，需交税。然而，商人约翰•尼克斯却认为，根据植物学定义，番茄属于水果，不应该被征税。于是，尼克斯直接将海关税收员告上法庭，要求退还被强制征收的税。

此案一路闹到了美国最高法院，直到6年后，法庭才做出最终裁定。法官认为：

"Botanically speaking, tomatoes are the fruit of a vine, just as are cucumbers, squashes, beans, and peas. But in the common language of the people … all these are vegetables which are grown in kitchen gardens, and which, whether eaten cooked or raw, are, like potatoes, carrots, parsnips, turnips, beets, cauliflower, cabbage, celery, and lettuce, usually served at dinner in, with, or after the soup, fish, or meats which constitute the principal part of the repast, and not, like fruits generally, as dessert."

“从植物学上讲，番茄是藤本植物的果实，就像黄瓜、南瓜、黄豆、豌豆一样。但在人们的日常语言中，这些都是种在菜园里的蔬菜。它像土豆、胡萝卜、欧洲萝卜、芜菁、甜菜、菜花、卷心菜、芹菜、生菜一样，无论生吃还是熟吃，通常都是在晚餐里搭配着汤、鱼、肉食用。它是正餐的一部分，而不像水果一样，通常作为甜点。”