A2. When we use reported speech, the main verb of the sentence is usually past (Paul said that …/ I told her that … etc.). The rest of the sentence is usually past too. (e.g. Paul said that he was feeling ill.)
a. We can leave out that. (e.g. Paul said that he was feeling ill. or Paul said he was feeling ill.)
b. In general, the present form in direct speech changes to the past form in reported speech: am/is -> was, are -> were, do/does -> did, have/ has -> had, will -> would, can -> could, want/ like/ know/ go etc. -> wanted/ liked/ knew/ went etc. (e.g. My parents are very well. -> Jenny said that her parents were very well.)
c. The past simple (did/ saw/ knew etc.) can usually stay the same in reported speech, or you can change it to the past perfect: had done/ had seen/ had known etc. (e.g. Direct: Paul said: I woke up feeling ill, so I didn't go to work. Report: Paul said (that) he woke up feeling ill, so he didn't go to work. or Paul said (that) he had woken up feeling ill, so he hadn't gone to work.)
A3. It is not necessary to change the verb in reported speech. If you report something and the situation hasn't changed, you do not need to change the verb to the past. (e.g. Direct: Paul said, My new job is very interesting. Reported: Paul said that his new job is very interesting. (the situation hasn't changed. His job is still interesting.))
a. You can also change the verb to the past. (e.g. Paul said that his new job was very interesting.)
b. but if you are reporting a finished situation, you must use a past verb. (e.g. Paul left the room suddenly. He said he had to go. (not has to go))
c. You need to use a past form when there is a difference between what was said and what is really true. (e.g. You met Sonia a few days ago. She said: 'Joe is in hospital.' (direct speech) Later that day you meet Joe in the street. You say: 'I didn't expect to see you, joe. Sonia said you were in hospital.' (not 'Sonia said you are in hospital', because clearly he is not))
Idiom 365
You can't Judge a Book by its Cover: don't prejudge the worth or value of something by it's appearance alone
Example: The candidate did not look very intelligent, but we can’t judge a book by its cover.