It is giving a command, so it is an imperative sentence.
i am going to SIT down and answer your question
Sit down or lay down for a moment.
"Sit down and hear" is a sentence fragment, as it lacks a subject and a main verb. To make it a complete sentence, you could add a subject and a verb, such as "Please sit down and hear the presentation."
the muscles starts streching every moment you sit down
yes
yes
"Sit down."That is a command.
Sit down and keep still.I wonder where I can sit.I don't want to sit there.
The naming part of the sentence is the subject, which is "you." It is the person or thing that the sentence is about.
"Please sit down in your jury box seat", said the judge to the juror.
Yes it is definitely. Sit quietly is an emphatic/command sentence. This type of sentence doesn't follow the usual S V O pattern of an English sentence. Other examples: Be quiet, sit down,
we are now going to sit down and behave like normal children............DENNIS sit down this very instant.