请问，在英语句子中，可不可以同时有过去时和现在时啊

当然可以阿

he does not know that you went to the hospital today
他不知道你今天去医院了
过去+现在

he will find out that you lied to him
他会发现你对他撒谎的
过去+将来

严格来说是可以的。比如：我相信他昨天没来学校。
I believe he didn't come to school yesterday.

当然可以
例子 ，我以前很有钱，但我现在一无所有
I was rich but now I am broke

将来与过去,也可以
I will strive to be different from who I was

过去时和现在时可以同时出现,一般是从句.如
I think she was ill last week.

将来与过去不可连用，要不时间上说不通了，一般用过去将来时，如

I would have married when I am 30 yeas old.

可以，比如在宾语从句中，主句可以是过去时，而从句如果是一个”真理”就可以仍然用一般现在时．
My teacher said that the earth goes around the sun.