Above and over are both used to talk about position and height. If something is higher than something else and the two things are imagined as being positioned along a vertical line, you can use either above or over. He opened a cupboard above the sink... She leaned forward until her face was over the basin. However, if something is higher than something else but the two things are regarded as being wide or horizontal rather than tall or vertical, you have to use above. The trees rose above the row of houses. Above and over are both used to talk about measurements, for example, when you are talking about a point that is higher than another point on a scale. Any money earned over that level is taxed. ...everybody above five feet eight inches in height. You use over to say that a distance or period of time is longer than the one mentioned. ...a height of over twelve thousand feet... Our relationship lasted for over a year. Above and over are also both used to talk about people's rank or importance. You use above to talk about people who are more important and in a higher position than other people. ...behaving as if she was in a position above the other staff. If someone is over you, they give orders or instructions to you. ...an officer in authority over him.

above和over均可表示位置和高度。若一物高于另一物，且两者可设想成处于同一垂直线上，则两词都可用：He opened a cupboard above the sink（他打开水池上方的碗柜），She leaned forward until her face was over the basin（她俯身向前，把脸凑到了脸盆上方）。当一物高于另一物，但两者宽而不高，或存在水平而非垂直关系，则须用above：The trees rose above the row of houses（树木矗立在那排房屋的边上）。above和over都可表示度量，例如表示一点在标度上高于另一点：Any money earned over that level is taxed（超过这一标准的收入都要纳税），everybody above five feet eight inches in height（所有身高超过5英尺8英寸的人）。over可用于距离、时间的比较：a height of over twelve thousand feet（超过1.2万英尺的高度），Our relationship lasted for over a year（我们的关系持续了一年多）。above和over都可指人的级别和重要性。above用于表示比他人重要和地位较高者：behaving as if she was in a position above the other staff（表现得好像她比其他员工职位高似的）。over用于表示某人有权下命令或指令：an officer in authority over him（一位军阶在他之上的军官）。