我有一本中文書 但我看不懂 it 毋須指出 因為前面已經提過了 除非要刻意強調 如 我有一本中文書 但我實在看不懂這本書 單獨 說 "那" 說"這"更奇怪了 我有十元 但遺失了 毋庸說 我有十元 但遺失"它"了 十元已經被提示過了 再說一次 它 沒有意義 can't 有許多表達方式 須視後方動詞 與漢語習慣表達 列舉一二 I can't read it. 我看不懂 I can't see you. 我看不到你 I can't hear you. 我聽不到 I can't afford it. 我負擔不起 I can't stand up. 我站不起來 I can't tell you. 我不能跟你說 I can't do it. 我做不來 I can't sleep. 我睡不著 I can't wait. 我沒辦法等下去

我有一本中文书，可是我看不懂中文字。 There is no need to say "it" here.

我有一本中文书，但我读不懂。You don't have to say "it" in Chinese, because "it" here can only means the book, so we could omit it.

can and can't : ability 能/会 (OK, I give up~!!!Really dont know how to explain)

我 有 一 本 中文 书， 但 我 不 能 看 它。