Sit down here.

Meaning: This means to move your body to a lower position and rest it on a chair, couch, or other surface.

Choice of Words: The verb sit means to rest one's body on a chair, bench, or other surface. Down means to move to a lower position. Here refers to the current location where the speaker is. When you put them together, "Sit down here" is an instruction asking someone to take a seat in the same place as the speaker.

Alternative Expressions

Related Expressions