1. I have seen the book you were reading.
2. I saw the book you were reading.
(What is thedifference between them?)
Actually, there's very little difference between these two sentences.
This site explains the past perfect tense you used in the first sentence.
http://web2.uvcs.uvic.ca/elc/studyzone/410/grammar/pperf.htm
Ms.Sue, did you not mean the present perfect tense?
Wouldn't the past perfect tense be:
"I had seen the book you were reading"?
EG, correct.
Ooops! Sorry. Thanks for catching my oo, E.G. and Bob.
You're welcome Ms. Sue - errare humanum est.
The difference between the two sentences is the verb tense. Sentence 1 uses the present perfect tense ("have seen") while sentence 2 uses the simple past tense ("saw").
1. "I have seen the book you were reading": This implies that the action of seeing the book happened at some point in the past and the speaker is emphasizing that they still have the knowledge or memory of seeing the book. The present perfect tense is often used when the time frame is not specified or when the action has a connection to the present.
2. "I saw the book you were reading": This simply states that the action of seeing the book happened in the past without any specific connection to the present. The simple past tense is generally used when the time frame is clear and there is no need to emphasize any present relevance.
So, the difference lies in the emphasis on the present knowledge or memory in sentence 1 using the present perfect tense compared to the simple statement of a past action in sentence 2 using the simple past tense.