up
The word 'su' in Italian is used to express the concept of upward movement or direction, similar to its English counterpart 'up'. It can be used as a preposition, an adverb, or even as a prefix in some cases. For example, 'salire su' means 'to go up', and 'alzare su' means 'to lift up'. It's also used in expressions like 'su e giù' which means 'up and down'.
The book is on that table.
In this phrase, 'su' indicates the location of the book, which is on the surface of the table.
I put the vase on a high shelf.
'Su' is used to describe the position of the vase, which is placed on top of a shelf that is elevated.
The photo is hanging on that wall.
'Su' indicates that the photo is mounted on the surface of the wall, showing its position in relation to the wall.