Hi, you can use the word across (-krôs, -krs) in 3 ways preposition. 1. On, at, or from the other side of: I ran across the street. 2. So as to cross; through: She drew lines across the paper. 3. From one side of to the other:I saw a bridge across a river. 4. Into contact with: I came across my old roommate. adverb. 1. From one side to the other: The footbridge swayed when I ran across. 2. On or to the opposite side: We came across by ferry. 3. Crosswise; crossed. 4. In such a manner as to be comprehensible, acceptable, or successful: We put our idea across; I had to get the message across to my boss. adjective. Being in a crossed position: He was seated with arms across.

1 - I went from one side to the other as I moved across the room. 2 - We walked across the bridge to get to the other side of the road. 3 - As a child he used to lay sideways across the bed but now he is too big :-)