英语主句与从句的时态关系

主从句时态一致原则是指：1.如果主句是一般现在时态或现在完成时态,从句常根据需要选择适当时态.如：The teacher says that he will go to the Great Wall next week .He tells us that he had an accident the other day .2.如果主句是一般过去时态,从句常用过去的某种时态；但从句如果是客观的真理或事实,仍用一般现在时态表达.如：He said that he would go to visit the Great Wall the next week .The teacher told us that the sun rises in the east .