大材小用 to use a big talent for a small task
Explanation
这个成语比喻人才使用不当，不能尽其才。它常用来批评那些只顾自己利益，而不考虑人才的使用价值的人。
This idiom means that talents are not used properly and cannot be fully utilized. It is often used to criticize those who only care about their own interests and do not consider the value of talents.
Origin Story
三国时期，蜀汉名将诸葛亮十分器重庞统的才华，但是庞统却长期得不到重用，最终被刘备委任为耒阳县令，这个职位对于庞统来说实在是大材小用。庞统心中郁闷，经常借酒消愁，直到后来在张飞的推荐下，才被诸葛亮委任为副军师中郎将，并参与了北伐战争。这个故事告诉我们，人才的使用一定要合理，不能让宝贵的人才被埋没，否则将会造成很大的损失。
During the Three Kingdoms period, Pang Tong, a talented military strategist of the Shu Han dynasty, was highly regarded by Zhuge Liang, but he was not given a chance to demonstrate his abilities for a long time. Eventually, he was appointed by Liu Bei as the county magistrate of Leiyang, a position that was far below his capabilities. Pang Tong was unhappy and often drowned his sorrows in alcohol, until he was eventually recommended by Zhang Fei and appointed by Zhuge Liang as deputy military advisor, taking part in the Northern Expedition. This story teaches us that it is important to use talent wisely and not let valuable talent go to waste, as it can lead to great losses.
Usage
当一个人有很大的能力，但却没有得到充分发挥时，就可以说“大材小用”。例如，如果一个优秀的程序员只是负责一些简单的代码修改工作，那么就可以说他“大材小用”。
When someone has great abilities but is not fully utilized, you can say "to use a big talent for a small task". For example, if an excellent programmer is only responsible for simple code modifications, then you can say he is "using a big talent for a small task".
Examples
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他明明很有能力，却只让他做一些简单的事，真是大材小用。
ta ming ming hen you neng li, que zhi rang ta zuo yi xie jian dan de shi, zhen shi da cai xiao yong.
He is so talented, but he's only given simple tasks. It's such a waste of his talents.
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在公司，我们需要充分发挥每个人的才能，避免大材小用。
zai gong si, wo men xu yao chong fen fa hui mei ge ren de cai neng, bi mian da cai xiao yong.
In the company, we need to give full play to everyone's talents and avoid wasting them.