on：表面有接觸，A在B上面，如書在桌上，書和桌子相接觸。above：無接觸，泛指上方，高于，如鳥在水面上，鳥相對于水來講位置處于上方。over：正上方、垂直上方，可接觸，可不接觸，B在A籠罩范圍之內（A燈在上方，B下方的在燈光范圍內）。

Above的用法

1.PREP介詞…上方;高于Apartment 46 was a quiet apartment, unlike the one above it...

和它樓上的那間不同，46號公寓很安靜。

He was staring into the mirror above him.

他盯著在他上方的鏡子。

2.ADV副詞上述;在上文【搭配模式】：ADJ Several conclusions could be drawn from the results described above...

從上文描述的結果中可以得出幾個結論。

Full details are in the table above.

詳細信息請見上文表格。

Above也是個名詞

For additional information, contact any of the above.

如需更多信息，可與以上任何一處聯系。

Above也是形容詞

For a copy of their brochure, write to the above address.

欲索取其宣傳冊，請寫信至以上地址。

3.PREP 介詞（數量或度量）在…以上，超過 If an amount or measurement is above a particular level, it is greater than that level.

The temperature crept up to just above 40 degrees...

溫度攀升至40度出頭。

Victoria Falls has had above average levels of rainfall this year...

維多利亞瀑布今年的降雨量超過了平均水平。

These plants must be stored in the light at above freezing temperature...

這些植物必須放置于零度以上光照充足的地方。

Government spending is planned to rise 3 per cent above inflation.

政府開支擬訂高出通貨膨脹3個百分點。