表示靜態意義，意為“在…的另一邊”。如：
My house is just across the street. 我家就在街道對面。（介詞用法）
We leave Dover at ten and we should be across in France by midnight. 我們10點鐘離開多佛，午夜時應能抵達法國那邊。（副詞用法）
2. across from與from across都可以說，但含義稍有區別：
(1) across from 表靜態意義，意為“在對面”，與opposite同義，此時也可省略from只說across。如：
Just across from our house there’s a school. 就在我們房子的對面有一所學校。
I’m staying at a little hotel just across from the Libyan Embassy. 我住在利比亞大使館正對面的一所小旅館里。
(2) from across 則表動態意義，意為“從……的對面”。如：
He shouted to me from across the room. 他從房間的另一邊向我喊。
They waved at us from across the room. 他們從房間那一頭向我們招手。