First, we must acknowledge the fact that throughout human history, people have violently and peacefully, through literature and other media called and cried for class equality. This shows a clear mandate for communism or a very similar principal, where value cannot be measured by how wealthy you are and there's one common social class.
How would such a state work: Government departments identical to workers unions. You establish a system in which each type of labour is compiled into separate unions and they elect a union representative (with a max time of say 3 years). (Union of teaching, union of raw resources, union of medical workers, union of construction and craftwork, etc.) The representatives from the unions go forward to be a government representatives. This way, when matters come up that the government need to discuss, all working class people are covered by proportional representation. Also this system allows centralization of industry, the goal of communism. This system also abolishes political parties with upper-class conservative reps.
In a Communist society, all crime to do with stealing money can be caught much quicker. Also, if it is not a dictatorship , then it works perfectly well if the country is willing to trade with other countries and makes profit not for one person, but so everyone to live with what they need. Also, everyone will work on what they like and are good at, and not on what is the most well paid and so everyone can live ideally because everyone works on what they are good at. Communism only never worked before, because it was mainly a dictatorship.
No, communism cannot work, because communism does not work to people's natural incentives. People act in their own self-interest. If a person does not have to work in order to earn more money, they will not work. People will not put in extra effort in order to succeed if they have the same no matter what they do. People are not that altruistic.
No, communism cannot work in reality only in theory. Communism cannot work because of greed. In my opinion, it is because it is based on assumptions that run counter to human nature. For example, you are supposed to not be motivated by wanting more (money, food, better house), but I don't think there are any humans who would not want a better life for themselves and their family.