after
[ˈɑ:ftə]
prep.
(表示时间)在…以后
After the play they called for the author to show himself.
剧终之后他们请求编剧和大家见面.
(表示位置、顺序)在…后面
The King came in,with all his servants following after him.
国王走了进来,所有侍从跟在他的后面.
(表示原因)由于,鉴于
She succeeded in solving the problem after hard work.
由于努力干,她终于解决了那个问题.
(表示条件)与…一致; 符合
He was built after his father.
他的体型像父亲.
(表示方式)像,仿照
This box is made after a new pattern.
这箱子是仿照新样式制作的.
(表示依据)以…之名命名
The boy was named Tom after his grandfather.
这小孩按他祖父的名字被起名为汤姆.
(表示论及)关于; 涉及
He inquired after your health.
他询问你的健康状况.
(表示目标)追求,追寻
There were always lots of men after her because she was clever as well as pretty.
总有许多男人追求她,因为她既漂亮又聪明.
(表示让步)尽管,仍然
After all my advice,he still went his own way.
在我苦口婆心地相劝后,他仍然一意孤行.
conj.
在…以后
After he goes,we shall eat.
他走之后,我们就吃饭.
adv.
以后,继后
They arrived soon after.
他们没多久就到达了.
past
[pɑ:st]
adj.
pass的过去分词
过去的,刚结束的(指时间可用在名词前面或后面)
前任的,曾任的
【语】过去的
老练的
the past week
上星期
in times past
好久以前
the past president
前任总统
the past tense
【语】过去式
词性变化
past
[pɑ:st]
n.
过去,往事
过去的生活,经历
【语】过去时; (动词的)过去式
We know nothing of his past.
我们一点也不知道他的过去.
at the weekend 强调的是一个具体的时间,在具体的时间点前用at,是它的一般用法.如：
I don't work at the weekend.
我周末不工作.
但如果强调的是一个特定的周末,就不能用at而要改为on.
如：Jack was killed on the weekend of May Ist,1987.
吉克被杀死在1987年5月1日的周末.
这个原则也适用于其它的时间介词.如：
On a cold morning,I opened the window and was glad to find that it was snowing outside.
在这个句子中就不能用“in”了,因为它是一个特定的早晨.
所以on the weekend和at the weekend是不能划等号的.
没有in the weekend的说法
表示“在运动场(上)”“在操场(上)”playground前既可用in,也可用on,但以用in为普通：They are playing baseball in [on] the playground.我的同学在运动场上打棒球
