I was looking into how to express "except" or "including" in Korean and my main source for this question is How to study Korean Lesson 71.
The word 포함하다 means "to include" whereas 제외하다 means "to exclude". Both of them are often used in passive form by changing 하다 into 되다. For example,
- 이 뷔페가격은 포도주가 포함돼요 = This buffet price includes wine/Wine is included in the buffet price.
- 이 뷔페가격은 포도주가 제외돼요 = This buffet price includes wine/Wine is not included in the buffet price.
But 포함하다 can be used within a sentence using 포함해(서). For example,
저를 포함해 여기에 네 명이 있어요 = Including me, there are four people here
On the other hand, 제외하다 can be used within a sentence using either 제외하고 or 제외한. For example,
나비를 제외한 모든 동물이 싫어요 = 나비를 제외하고 모든 동물이 싫어요 = Except for butterflies, I don’t like any/all animals.
The website linked at the beginning of the question says that though expressions like 포함하고 or 포함한 or 제외헤서 would be understood, there are not natural.
I fail to understand that asymmetry. Is there a logical (i.e. grammatical) reason for it?
From what I know of Korean grammar, 아/어/여서 means a consequence or a connection (rough English translation: "so"), while 아/어/여고 means a connection ("and") and (으)ㄴ is the adjective form of a descriptive verb.