Properties {get;set;}

Hi,

I have some problems with {get; set;} thing, hope you could help.
So I have a class:

class Parts
  {
  public Vector2 partPos { get; set; }
  public bool moving { get; set; }

  /*public Parts()
  {

  }*/

  //private Vector2 PartPos;
  /*public Vector2 partPos
  {
  get
  {
  return PartPos;
  }
  set
  {
  PartPos = value;
  }
  }*/
 
 //private bool Moving;
  /*public bool moving
  {
  get
  {
  return Moving;
  }
  set
  {
  Moving = value;
  }
  }*/
  }

Problem is that I can't modify only the X or only the Y coordinate of Vector2 partPos (I have to create a new Vector2 and then set it to partPos). Is there any way of doing that with get set properties? Because this part of code is not acceptable:

public float partPos.X {get; set;}

Also I have thought about  adding this line of code:

public float partPosX { get { return partPos.X; } set { partPos.X = value; } }

, but it's also not acceptable because partPos is not a variable.
I think I don't get something here :/.
Thanks in advance for any help!