"Where do you put the salt?"
Translation:Dove mettete il sale?
Commonly Italians say a sentence without personal pronouns for example : "Mangio il panino" "Guardiamo la telivisione" For italians the question such like that doesn't need "tu" it just makes the sentence more complicate. But you can use personal pronouns to clearer the sentence , for example : "Dov'è ?" Means where is he/she/it ? For clearer you can say "Dov'è lui ?" Where is he ? So , the personal pronouns used only in some cases . Thank You
Mettete is plural you so it would have to be voi mettete - you plural seems to be used quite a lot for example in restaurants, shops and you would use plural if talking to a group eg at someone's house. for one person a friend you would use metti - you don't need the tu as the verb ending tells you who you mean (likewise you don't need voi as the ete ending tells you who).