反覆、重複

In Traditional Chinese, most commonly used is 反覆，not 反復，and then if you want to say 重複 it’s a different word. I think the best way to remember is that it is how it is. 🫣

覆 contains the component for “to cover” or “to flip” (like a lid), the 覀 on top. Imagine a pancake being flipped. You flip it over, then back again.

複 has the radical 衤 which is also known as 衣 makes you think of clothes so you have layers and layers of clothes. Imagine layers of clothing. You aren’t “flipping” your shirt; you are putting one layer on top of another “duplicate” layer.

For example:

這段錄音很不清楚，我反覆聽了好幾遍才聽懂。
This recording is very unclear; I listened to it over and over (carefully/repeatedly) before I finally understood it.

You are “turning the audio over” in your mind to extract meaning.

這首歌太好聽了，我整天都在重複聽。
This song is so good, I’ve been listening to it on repeat (again and again) all day.

You are simply “duplicating” the experience because you enjoy it.