Student or Learner
->indirect speech: he said (that) he was sad
So i understand that he was sad when he said it, but I just can't give a clear explanation, why?why do we know that it happens at the same time?
Ok, so if he said he had checked the door means he had checked the door before he said it,if he said he understood ,he understood at the moment when he said it,if he said he would do it means he would do it after he said it ,right?
You'd have to decide from the context.
"He said that he was unconcious for a few minutes". This can only mean, "He said, 'I was unconscious for a few minutes."'
If you really need to make a distinction in reported speech, you can say, "He said that he had been sad/unconscious." But that doesn't help if the speaker uses the simple past in indirect speech.