"Eat up" is a phrasal verb that means to consume something completely or in large amounts. It can refer to food, as in "Eat up your dinner", meaning to finish eating everything on your plate. It can also be used metaphorically to describe using a lot of something. For example, "This old truck eats up gas" means the truck consumes fuel quickly or inefficiently. Similarly, you can say "That app eats up battery life" to mean the app drains the battery fast.

「eat up」是一個非常實用的動詞片語，最基本的意思是「把東西吃光、吃完」，所以媽咪常催小孩說：Come on, eat up your vegetables! 這裡的 eat up 帶有「不要剩、全部吃完」的語氣。除此之外，eat up 也可以延伸表示「耗盡、佔去（資源或時間）」；例如：The repairs ate up all my savings. 就是說維修把我所有的積蓄都花光了。另外，在口語對話裡有人會用 it eats me up 來形容某件事「折磨、困擾」他們，像：The guilt is eating me up inside. 所以記住，eat up 不只跟真正的吃有關，還可以用來形容耗費、侵蝕的概念。

"Fill up" has a few common meanings, all depending on the context. First, it can mean to put something into a container until it's full, like, "I need to fill up my water bottle." Second, it can describe eating or drinking until you're full, as in, "That pasta really filled me up." And third, it can be used when a place becomes full of people, like, "The restaurant started to fill up around 7 p.m." It’s a flexible, everyday phrase that just means something—whether it’s a tank, a stomach, or a room—is getting full.

看到 “fill up” 這個片語時，可以想像把空的容器補滿的畫面，它最常用來表示「把…裝滿／加滿」的意思，尤其常聽到人們說 “fill up the gas tank”（把油箱加滿）或 “fill up your cup with coffee”（把你的杯子倒滿咖啡）。此外，當我們在餐廳聽到服務生問 “Would you like me to fill up your water?”，就是在詢問要不要續水；若是人很飽，也可以說 “I’m all filled up” 來表示吃得很撐。記得 “fill up” 通常後面可以直接接受詞，也可以搭配介系詞 with 來說明「用什麼填充」，例如 “She filled up the form with her personal information.” 用法簡單，但要注意別和單純的 “fill” 混用，因為 “fill” 強調「填入／填寫」，而 “fill up” 則帶有「填到滿」的概念喔！