1. I have read the book.
2. I read the book.
The first one is absolutely clear but the second one freaks me out. Is it a present or past tense; who knows. Is there are some reasons to write exactly like that? This word has another pronunciation in past tense and I can't understand why it isn't written as 'red'.
For example:
1. I have red the book.
2a. I read the book. (present)
2b. I red the book. (past)