我已经看完了用英语怎么说

"I have finished reading" 可以用 "I have read it" 或 "I have completed reading it" 表示。这是一个简单的句子结构，来源于英语的基本语法。

例句：

"I have read the book" (我已经读完了这本书)
"I have completed reading the newspaper" (我已经看完了报纸)
"I have finished reading the novel" (我已经读完了这本小说)