Object handle
All texts and movable objects have an object handle in the form of a blue square. Hard barlines can be recognized by having such an object handle.
For objects consisting of two parts (such as e.g. slurs, lines and crescendo marks) you will see two blue marks on the notation bar. These are the points of application or the beginning and end of, for example, an arc. When the cursor is on one of the object handles you can move that object with <alt->, <alt->, <alt->, <alt-> in the desired direction.
You can also change the objects properties is applicable. The context menu will show the relevant relevant properties. For example, at a crescendo-sign its opening width and boldness can be adjusted. The arc shape of a legato slur, same story. Thickness of lines at an object handle with <ctrl +> resp. <ctrl ->.