- expressing location or arrival in a particular place or position指所在或到达地点在; 在…旁：
they live at Conway House
他们住在康威豪斯
she was constantly at the telex machine
她一直待在电传机旁
they stopped at a small trattoria.
他们停在一家意大利小餐馆旁。
- used in speech to indicate the sign @ in email addresses, separating the address holder's name from their location（电子邮件地址中的）@符号。
- expressing the time when an event takes place指事件发生的时间在…时刻; 在…时候：
the children go to bed at nine o'clock
孩子们9点钟上床
his death came at a time when the movement was split
就在运动四分五裂时他去世了
he was defeated at the election of December 1910.
他在1910年12月的选举中被击败了。
- (followed by a noun without a determiner) denoting a particular period of time后接不带限定词的名词在…期间; 在…时刻：
the sea is cooler at night
夜间海水更凉
the force landed at dawn.
部队在凌晨登陆。
- (followed by a noun without a determiner) denoting the time spent by someone attending an educational institution, a workplace, or their home［后接不带限定词的名词, 指某人在校、在工作单位或在家的时候］在…时：
it was at university that he first began to perform
他最初开始演出是在大学时
we all need to get involved in fighting crime whether it's at work, at home, or at school.
不论在工作, 在家, 还是在学校, 我们都必须参与打击犯罪。
- denoting a particular point or segment on a scale指度量上的某一点或某一段以; 达：
prices start at £18,500
以18,500英镑起价
driving at 50 mph
以每小时50英里的速度行驶
learners of English at advanced levels.
高级英语学习者。
- referring to someone's age指年龄在…岁时：
at fourteen he began to work as a postman.
14岁时他开始干邮递员的工作。
- expressing a particular state or condition处在…状态：
with a ready smile to put Mrs Jones at ease
总带着微笑好让琼斯夫人放松
placed them at a serious disadvantage
置他们于极度不利之地
the coroner accepted that the machines were at fault.
验尸官承认是机器出了错。
- expressing a relationship between an individual and a skill在…方面：
boxing was the only sport I was any good at
拳击是我惟一擅长的体育项目
he is poor at giving instructions.
他不善于发号施令。
- expressing the object of a look, gesture, thought, action, or plan向, 朝; 对于：
I looked at my watch
我看了看手表
Leslie pointed at him
莱斯利朝他指了指
I was amazed at how well the hair kept its shape
我惊诧于发型保持得如此之好
policies aimed at reducing taxation.
旨在降低税收的政策。
- expressing the target of a shot from a weapon（武器）瞄准, 以…为目标：
they tore down the main street, firing at anyone in sight.
他们捣毁了大街, 朝看见的每个人开火。
- expressing an incomplete or attempted action, typically involving repeated movements（尤指反复的动作）（抓）住; （抓）向：
she clutched at the thin gown
她抓住那件薄薄的睡衣
Shelley grabbed at his arm.
雪莱一把抓住他的手臂。
- expressing the means by which something is done指方法、途径用, 以：
holding a prison officer at knifepoint
用刀尖顶住监狱官
figurative 〈喻〉her pride had taken a beating at his hands.
她的骄傲受到了他的打击。
at all
- 见ALL.
at first
- 见FIRST.
at it
- engaged in some activity, typically a reprehensible one在从事（应受指责的）活动：
the guy who faked the Hitler diaries is at it again.
那个伪造希特勒日记的家伙又在胡编乱写了。
at last
- 见
LAST1 .
at least
- 见LEAST.
at most
- 见MOST.
at once
- 见ONCE.
at that
- in addition; furthermore而且; 此外：
it was not fog but smoke, and very thick at that.
那不是雾而是烟, 而且很浓。
not at all
- 见NOT.
where it's at
- informal the fashionable place, possession, or activity〈非正式〉时髦的地方（或物品、活动）：
New York is where it's at, stylewise.
纽约是时尚方面的好去处。
where someone is at
- informal someone's true or fundamental nature or character〈非正式〉禀性, 本性：
I think we've got enough information to have an idea of where he's at.
我想我们已经掌握了足够的情况, 对他的本性大致有了一个了解。