说来话长。(Shuō lái huà cháng.)It cannot explain all that in just a few words; It's a long story.

Explanation

“说来话长”表示事情很复杂，不是几句话就能说清楚。
“说来话长” （shuō lái huà cháng）usually indicates something is so complicated that cannot be explained all in just a few words.

Words:

留学liúxué:study abroad;
收获shōuhuò:learned a lot.

Senteces

1、Jiă: Nǐ búshì dǎsuàn qù yYīngguó liúxué ma? Zěnme tūrán gǎibiàn zhǔyi le?
甲：你不是打算去英国留学吗？怎么突然改变主意了？
A: Aren’t you planning to study abroad in Britian? Why do you suddenly change your mind?

Yǐ: āi, zhè shì shuō lái huà cháng, yǐhòu yǒu shíjiān mànman gēn nǐshuō.
乙：哎，这事说来话长，以后有时间慢慢跟你说。
B: It is a long story. I will tell you later.

2、Jiă: Nǐ néng gēn wǒ shuōshuo zhè cì qù Běijīng de gǎnshòu ma?
甲：你能跟我说说这次去北京的感受吗？
A: Can you tell me how about your trip to Beijing?

Yǐ: Shuō lái huà cháng. Zǒngde láishuōshōuhuò hěn dà!
乙：说来话长，总的来说收获很大！
B: It would take long to tell in full. But generally speaking I learned a lot!

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