直接宾语改为间接宾语什么情况时态不变?

①直接引语是客观真理。"The earth moves around the sun and the moon moves around the earth, the teacher told me。 → The teacher told me the earth moves around the sun and the moon moves around the earth。②直接引语是过去进行时,时态不变。如：Jack said。 "John, where were you going when I met you in the street?"→Jack asked John where he was going when he met him in the street。③直接引语中有具体的过去某年、某月、某日作状语,变为间接引语时,时态不变。如：Xiao Wang said。 "I was born on April 2l, 1980。" →Xiao Wang said he was born on April 20, 1980。④直接引语如果是一般现在时。表示一种反复出现或习惯性的动作,变间接引语,时态不变。如：He said, "I get up at six every morning。" →He said he gets up at six every morning。⑤如果直接引语中的情态动词没有过去时的形式（例：ought to, had better, used to)和已经是过去时的形式时,（例：could, should, would, might）不再变。如：Peter said。 "You had better come have today。" →Peter said I had better go there that day。