Close can be followed by the prepositions “down”, “in” or “up”. Close in or up are used when referring to something or somebody that is coming nearer. Close up means shut permanently a shop or a business.

Prasal verb Translation Examples
Close down (transitive) chiudere definitivamente In spite of all his efforts he had to close down his business.
Close down (intransitive) chiudere definitivamente The jewellery shop was closed down after the third robbery.
 Close in (intransitive)  avvicinarsi When we saw that the hurricane was closing in we decided to leave immediately.
Close up (intransitive) avvicinarsi di persone His friends closed up a bit to let him seat on the same bench.
Close up (intransitive) avvicinarsi di persone As there was a lot of noise he closed up to her to let him hear.