difference between sit, sit down, take a seat, have a seat

sit  - (суусан байрлал авах, суух)sitting - being in a seated position --- энэ суугаа байрлалд байна уу гэсэн санааг илтгэнэ
1 [intransitive] to be in a position on a chair, etc. in which the upper part of your body is upright and your weight is supported at the bottom of your back
       ---- She sat and stared at the letter in front of her.
2 [transitive]to put someone in a sitting position
sit someone + adverb/preposition
      ---- He lifted the child and sat her on the wall.
sit down - (суух, доошоо суух)sitting down - moving to a sitting position from a standing position
“Please sit down” and “please be seated” are more directive.  "please sit down" is more of an order
      ----  He sat down on the bed.
take a seat - (суун уу, суудал эзэлнэ үү, суудал эзлэх)"take a seat" is slightly more commanding in tone than "have a seat"
have a seat - (суун уу, суудал эзэлнэ үү, суудал эзлэх)"have a seat" is of more friendly approach 

difference between sit and sit down

• sitting down - moving to a sitting position from a standing position
  
  sitting - being in a seated position

difference between take a seat and have a seat

• though both of them have an equal meaning, I think "have a seat" is of more friendly approach and "take a seat" is a bit sounding like a command (it's like "grab a chair then sit down"). 

• i think there is no difference between the two phrases.

• Hi... Yes the meaning is the same... Don't worry!

• romulus is right. 
  "take a seat" is slightly more commanding in tone than "have a seat" which is more like offering a chair. 
  The difference is very slight though.

• "Take a seat," at least in America, is used in more formal situations and when you are usually the one in charge of the person you're talking to. It's more directly telling someone to take a seat, whereas "have a seat" is more implying that you're offering it to them in a more friendly way. I'd almost never say "take a seat" to a friend; I'd say "have a seat" instead.
  
  In the UK there may be no difference between the phrases, so it depends on which you'd like to learn.

difference between sit down and have a seat

• In general, "have a seat" is more polite; "please sit down" is more of an order. A teacher might tell her students, "please sit down". A host would be more likely to say to a guest, "have a seat".

• I don't think this is right at all. At least in the U.S., saying "Have a seat" could certainly be an invitation rather than a command. "Please sit down" might be an order, but when you add a comma, "Please, sit down" that becomes an invitation as well. "Won't you have a seat?" and "Will you sit down?" sound weird to me in general, but if someone said one of those to me, I would take it as an indirect order.

• In this context, I would say “please have a seat”. You're inviting the person to sit down, but not formally request that they sit down, merely offering the possibility.
  “Please take a seat” is also possible, but slightly less deferential. It tends to be used in contexts where the person really should sit, for example by a doctor talking to a patient.
  “Please sit down” and “please be seated” are more directive. For example, an air hostess might tell a passenger on a plane to “please be seated”, because the passenger really must seat while the aircraft is in motion. However, tone is key: it is possible to say “Please, sit down” (or perhaps that should be “Please! Sit down!”), with a pause after “please” and the right intonation, to convey that you are happy to see the person and cordially inviting them to sit down.
  
  
  
  

Thesaurus: sitsit down   have/take a seat  perchThese words all mean to rest your weight on your bottom with your back upright, for example on a chair.sit to rest your weight on your bottom with your back upright, for example on a chair: May I sit here? Sit still, will you!NOTE Sit is usually used with an adverb or a prepositional phrase to show where or how someone sits, but sometimes another phrase or clause is used to show what someone does while they are sitting: We sat talking for hours.sit down to move from a standing position to a sitting position: Please sit down.have/take a seat to sit down NOTE Have/Take a seat is used especially as a polite way of inviting someone to sit down: Please have a seat.perch (somewhat informal) to sit on something, especially on the edge of something: She perched herself on the edge of the bed.NOTE Perch is always used with an adverb or prepositional phrase to show where someone is perching.