基本分类介词atin基本用法多用于具体时刻或固定搭配表示一段时间，如年，月，日，世纪，四季等；特殊用法可以表示“从现在起多长时间以后或以内; 固定搭配用在具体的某一天以及具体某一天的早上下午晚上等，或者某一具有特殊特征的早上下午或晚上两者都用于完成时，表示从某时一直延续onsincefor时间介词frombefore至今；since后接时间点，for后接时间段从„始，说明开始的时间；表示时间后接时间点，意为：在„之前，1表示在以过去为起点的某一段时间之后，用于过去时；after2与时间点连用表示在将来的某个时间之后；during“during+时间段”表示在某段时间期间；through表示“一直，由始至终”until表示“直到„才”/till表示“到„为止”，后接时间点by基本用法用在较小的地点前用在较大的地点前表示“在„上面”，一般有接触面指“在„正上方”，指没有接触面的正上方, 反义词是under。表示“在„上面”，指没有接触面的上方,在高一些的位置, 反义词是below。表示“在..下面”，不一定有垂直在下之意表示“在..正下方”表示“在„前面”（范围外）基本分类介词atinonoverabovebelowunderinfrontofin the地点介词frontofbeforeat theback of表示“在„前面”（范围内）表示位置时与in front of相同表示“在„后面”与in the front of 是反义词bybesidenearnext tobetweenamongacross都表示“在„旁边”“在„附近”，距离比by和next to远“紧邻，在„旁边”，相当于close to“两者之间”可指人也可指物“三者或三者以上之间”可指人也可指物across 是介词，cross是动词，两者都表示从表面横穿through“从空间横穿”alongin方位介词ontowithby方式介词in\"沿着\"表示一个地方在另一个地方的范围内表示两地相隔表示两地相隔 表示使用的工具或手段表示一种方式或方法，后接的名词不加冠词也无复数形式，也可跟动名词表示材料或语言例子at seven; 固搭：at night, at noonin spring, in 1990; 固搭：in themorning/afternoon/evening;They will finish the work in an hour.一小时后他们将完成这份工作。on Children's Day; on June 1st; on a coldmorning; on a Friday evening;He has studied English since 2003.He has studied English for 10 years.From now on, I will get up early to study.I have to finish this before dinner.They finished the work after two years.I'll call you after two O'clock.He lives with us during all these years.We worked hard through the winter.I waited for my mother until she came home.We have learned 1000 English words by theend of last term.例子at the bus stop; at the train station, atthe villagein London;Look at the book on the table.There is a bridge over the river.Raise your arms above your head.The coat reaches below the knees.There are many bikes under the tree.There are some trees in front of the house.He sits in the front of the classroom.He sits before me. He sits in front of me.There is a blackboard at the back of ourclassroom.We live by the river.Who's that girl beside the boy?Is there a hospital near here?The boy next to her is my classmate.You must choose one between her and me.He is the tallest among all the children.Go across the street and then turn right.Cross the street and then turn right.It took us ten minutes to drive through thetunnel.He likes to drive along the river.Shenzhen is in the southeast of Guangdong.Russia is on the North of China.Changsha is to the north of Guangzhong.You must write this letter with a pen.I go to school by bus.My sister makes a living by sellingnewspapers.You must write this letter in black ink.What's this in English?