關於英文句型問題。?

名詞子句在當動詞受詞時，其時態可決定時效。
The police told Jessie that they would bring her antiques back after the thief went to jail.
子句動詞都用了過去式，表示時效不及現在，是歷史事件：即「當時」警方是這麼說的。
would bring是「過去的未來」，所以是發生在went（過去簡單式）之後，合乎邏輯。

The police told Jessie that they "will bring" her antiques back after the thief "goes" to jail
警方所述仍有效（或現在尚未發生）。提供未來時間點的副詞子句用「現在簡單式」動詞。

They did not know that the earth "is" round.不變的真理不改時態。

She said she'll make the tea. （I am reporting an immediate future event.)
She said she would make the tea. （I am reporting a past event.)

單純只是原句，如何得知小偷還未坐牢?
如果這是一篇文章，就可清楚看出作者的敘事觀點。若是單就這兩句話，就加上一點推測。
注意原句說話的時間點是過去，told，這可以是就記憶所及描述過去事實。

1.) 如果我們改採引述的寫法，
The policeman told Jessie, "they (have) found the antiques from her store in a pawn shop. They will bring them back to her after the thief goes to jail."
將引述句改成子句的寫法，就成了原句，引述內容完全是一過去的陳述。(至於小偷坐牢了沒有，非關文旨)

2.) 如果說話的當下，是採用現在式敘事，
The policeman tell Jessie that they have found the antiques from her store in a pawn shop.They will bring them back to her after the thief goes to jail.

一句話的存在，有其發生的情境。句子只有在情境下合理使用，才有意義。好談文法者切記!!

The policeman told Jessie that they found the antiques from her store in a pawn shop.They would bring them back to her after the thief went to jail.

警察告訴Jessie 他們在當舖內 找到她店裡的古董。 等到小偷坐牢後，他們將帶回那些古董還給Jessie。

其實在英文文法內，"一句話內前後最好"是用相同的時態來陳述。至於為什麼這句話用過去式的原因是，前面警察在過去已經告訴他們找到古董　後面They would 代表著(告訴他們後但未達現今=依然等於過去)在他們坐牢後才會還給他們

後面應該要用went 而非go

此外陳述上的事件也非現今而是過去所發生的，所以一定是用Went!

"after the thief went to jail." 凡after之後多數是過去的事實;而且整件事情都已經發生成為過去屬於佈告性質. Yip