In my textbook, there is a sentence:
中国語の発音は難しかったが、漢字はあまり難しくなかった。
And there is also a sentence:
「日本史」は難しくなかったですが、「翻訳」は大変でした。
I'm confusing that is it still a correct expression with removing of the "です" in "ですが" in the second sentence?
If it is still a native expression, what's the differences between it and the original one?
難しい = (it) is difficult -- informal
難しいです = (it) is difficult -- polite
難しかった = (it) was difficult -- informal
難しかったです = (it) was difficult -- polite
難しくない = (it) is not difficult -- informal
難しくないです = (it) is not difficult -- polite
etc.
You get the idea.
For i-adjective conjugations putting です at the end changes from informal to polite style.
I think 「日本史」は難しくなかったが、「翻訳」は大変でした without the です would be awkward because the parts either side of が are independent statements, and the latter ends in でした which is in polite style. But note that this doesn't apply to all conjunctions.
