@learnativenglish: “I’m busy” is a very useful response in English, but sometimes it can come across a little rude or curt. Having an expanded vocabulary helps you soften your responses or explain just how busy you are. Study these alternatives to better explain why you haven’t been able to finish something or why you are declining an activity. Even if you don’t plan to use this words yourself, I guarantee you will hear others using them, so it’s important to understand what they mean.