I have always been wondering why do we have to say "I liked your book" instead of "I like your book". To me it feels like I only liked the book before when I was reading it but no longer at the time when I say that sentence.
Also, is there actually a rule about not using different tenses in one sentence? Which of the following sentences are correct?
1. I chose to major in science because I think it is an interesting subject.
2. I chose to major in science because I thought it was an intersting subject.
3. Whether or not I should have warned him before he got in the car is arguable.
4. Whether or not I should have warned him before he got in the car was arguable.
If number 2 is correct, then what if I still think science is an interesting subject now? Similarly, as for number 4, what if the issue is arguable is more of a fact?
Furthermore, can I still say "I've always wanted to be an actor" when I am already an actor? Or should I say "I'd always wanted to be an actor"?
I am also very confused as to whether I should use simple present tense or simple past tense to tell a story. I even found some native speakers like to start the story with past tense and then switch to present tense somewhere half way through the story.
Sorry for asking a lot of questions. I would really appreciate your help.
Thank you very much.