1. use your loaf —— 動動腦子
妳跟別人說這個習語，就是說用有點生氣的口吻讓別人做事多動動腦子。
e.g. I Going to be a useful boy, so long as you use your loaf .
只要運用妳的頭腦，就會成為有用的年輕人。
e.g. You haven’t even switched the thing on. Come on, Jamie, use your loaf!
妳連開關都沒看。天哪，傑米，長點腦子吧!
2.The lights are on but nobody’s home .
light意指燈，on意指亮著的，開著的，nobody意指沒有人，home意指在家;the lights are on but nobody’s home系指家裏燈亮著但沒有在家，喻指心不在焉，身在曹營心在漢。
e.g. She really has no clue- the lights are on but nobody’s home!
她完全抓不著頭緒——腦子笨的像頭豬。
e.g. Because the lights are on but nobody’s home, she cannot understand what the teacher is saying.
因為她心不在焉，所以根本不懂老師在說什麽。
3. all thumbs 笨手笨腳
Thumbs: 大拇指。如果壹個人十根手指都是大拇指，那連握東西都握不住怎麽幹活。
e.g. Dick isn't very good using tools around the house. He's all thumbs: when he hammers a nail he's likely to end up hitting his finger instead. And you'd be shocked to hear the bad language he uses when that happens!
Dick在家裏用工具幹活是不太行的。他總是笨手笨腳，當他要敲壹個釘子的時候，他往往會敲到他自己的手指上。把自己敲痛了，他就破口大罵，妳聽了真會嚇壹跳。
e.g. He’s all thumbs when it comes to his girlfriend. He just can’t do anything right!
他壹遇到他女朋友，就笨手笨腳的，什麽事都做不好。
4. not the brightest bulb in the box / on the tree / in the chandelier. 他/她可算不上最聰明的
字面意思就是：並不是盒子裏/聖誕樹上/吊燈裏最亮的燈泡。其實內在意思是很婉轉地在說妳笨。
e.g. He's not the brightest bulb, is he?
他還真不怎麽聰明，是吧?
5.bean brain 沒腦筋
腦子小得像顆豆那樣，到底能用不能用?答案：沒什麽用。
e.g. I can't imagine Bill is such a bean brain. He brought the camera and forgot the film.
無法想象比爾這麽沒腦筋。他帶了相機，卻忘了帶底片。
e.g. I have never seen a bigger bean brain like you.
我從沒見過比妳更蠢的蠢才。