楽しかった旅行です。-is this grammatically wrong?
So in my textbook for N5 students, it says
“Make the end of a sentence past tense when you want to use nouns and adjectives to explain in detail what something in the past was like.”

Also:
X 楽しかった旅行です
O 楽しい旅行でした

Anybody can explain the difference in both sentence?
Or do i just have to follow and get used to this rule?

Question

楽しかった旅行です。-is this grammatically wrong?
So in my textbook for N5 students, it says
“Make the end of a sentence past tense when you want to use nouns and adjectives to explain in detail what something in the past was like.”

Also:
X 楽しかった旅行です
O 楽しい旅行でした

Anybody can explain the difference in both sentence?
Or do i just have to follow and get used to this rule?

Answer

>Also:
>X 楽しかった旅行です
>O 楽しい旅行でした

I agree with this. 楽しかった旅行です is NG and I personally never have heard or said it, but it is not because this line violates the grammar rule; (adjvective-past)(noun)("desu") is grammatically possible, e.g. "母と暮らした子供の頃、それが私のいちばん楽しかった思い出です“.

楽しかった旅行です is like "It is a trip which was happy" while
楽しい旅行でした  is like  "It was a happy trip". No doubt, the latter is natural and usual. You should use the usual one if without any special reason. This is the reason I think the latter is a better one.

**** And it makes me wonder,  
Is it OK in Korean to say "楽しかった旅行です" like "즐거웠 던 여행입니다(?)" ?

Answer

It is a tough question. I am willing to think about it.