知乎问题：

我来回答：

大概情况是没有谁能说清更细节的原因。

换成现代单词的拼写形式的话，原始日耳曼语阶段的good-better-best对应的应该是：boot-better-best。这里的boot不是靴子这层含义，而是比如句子“what boots it to complain?”“抱怨有什么用呢？”

另外短语to make bot的意思就是to make good，这里的bot的意思就是“good”。比如图片中的话题叫：How to Make a Twitter Bot？你可以直接理解做：How to Make a Twitter Good？

但是后来good代替了boot/bot，只不过这个替换的原因我没有查到更为准确的原因。

这个替换发生在原始日耳曼语阶段甚至更早的pre-原始日耳曼语阶段，所以和1000多年后的维京人入侵没有任何关系。

Proto-Germanic原始日耳曼语什么时期？

Proto-Germanic is the ancestor of all Germanic languages, old as well as modern. It is a descendant of Proto-Indo-European. It was spoken in north mainland Europe and southern Scandinavia, more or less during the time of the Roman Republic...

https://en.wiktionary.org/wiki/Wiktionary:About_Proto-Germanic

Roman Republic什么时期？

The Roman Republic (Latin: Rēs pūblica Rōmāna [ˈreːs ˈpuːblɪka roːˈmaːna]) was the era of classical Roman civilization, led by the Roman people, beginning with the overthrow of the Roman Kingdom, traditionally dated to 509 BC, and ending in 27 BC with the establishment of the Roman Empire.

https://en.wikipedia.org/wiki/Roman_Republic

维京时代

The Viking Age (793–1066 AD) was the period during the Middle Ages when Norsemen known as Vikings undertook large-scale raiding, colonizing, conquest and trading throughout Europe, and reached North America.[1][2][3][4][5]

https://en.wikipedia.org/wiki/Viking_Age