耍廢废 shuǎfèi is casual, spoken-style slang for lounging around doing nothing productive — think lying on the couch all day in pajamas, scrolling your phone, and avoiding any responsibility. It’s playful and a little self-deprecating, very common among younger speakers in Taiwan, and shows up constantly in everyday chat. You’ll often hear it as 想耍廢废 xiǎng shuǎfèi (“want to be lazy”) or 耍廢废一整天 shuǎfèi yìzhěngtiān (“lazing around all day”).

If you only learn one, 但是 dànshì is the safe, all-purpose choice — it works almost everywhere. Reach for 可是 kěshì when the contrast comes with a bit of feeling behind it, like frustration or disbelief. Reach for 不過不过 búguò when you want to soften the blow — adding a small caveat rather than flatly contradicting what you just said.