过去了就过去了。(Guòqu le jiù guòqu le.)Let by gones be by gones.

Explanation

这个短句一般用做插入语，位于句首或句中。人们常用它来劝诫或安慰他人：不管过去发生的事情是好还是坏，它都已经过去了，不能重演或挽回了，所以，正确的做法是,不要再继续想这些事情了,重新开始，继续往前走。
This phrase is often used as a parenthesis, which appears at the beginning or in the middle of a sentence. People usual use this phrase to persuade or comfort others. The implication is whatever happened is in the past and cannot be repeated or changed; the right choice for you to do is letting it go and moving on.

Words:
考试kǎoshì:exam;
努力nǔlì:Try harder;
误会wùhuì:misunderstand.

Sentences

1、Jiă: Wǒ zhècì kǎoshì méi kǎo hǎo,zhēn nánshòu!
甲：我这次考试没考好，真难受！
A: I did poorly in the exam; I feel so bad about it!
Yǐ: Guòqu le jiù guòqu le, nǐ yǐhòu nǔlì diǎnr,zhēngqǔ xiàyícì kǎo hǎo le.
乙：过去了就过去了，你以后努力点儿，争取下一次考好了。
B: Let bygones be bygones. Try harder next time.

2、Jiă: Shàngcì chǎojià de shì,zhēn shì duìbuqǐ, shì wǒ wùhuì nǐ le.
甲：上次吵架的事，真是对不起，是我误会你了。
A: I am so sorry about the quarrel with you last time. I misunderstood you.
Yǐ: Guòqu le jiù guòqu le,dàjiā háishì hǎo péngyou.
乙：过去了就过去了，大家还是好朋友。
B: Don’t mention it. We are still friends.

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