Close the door behind you when you enter.

Meaning: This means to shut the door after you have entered a room or building.

Choice of Words: Close means to shut something, door refers to the hinged, sliding, or revolving barrier at the entrance of a building, room, or vehicle, and behind means at or to the back of something. When combined, Close the door behind you means to shut the door after you have entered.

Alternative Expressions

Shut the door after you come in.

Meaning: This means the same as the first sentence.

Choice of Words: Shut is another word for close. After means following something else. Come in means to enter a place.

Don't leave the door open when you go in.

Meaning: This means the same as the first sentence, but it tells you not to do something.

Choice of Words: Don't means do not. Leave means to let something stay in a place. Open means not closed. When means at the same time as something else happens. Go in means to enter a place.

Related Expressions