No, a black hole cannot become a star again in the traditional sense. Black holes are formed from the remnants of massive stars that have undergone gravitational collapse. When a star exhausts its nuclear fuel, it can undergo a supernova explosion, leaving behind a dense core. If the core's mass is above a certain threshold known as the Chandrasekhar limit (around 1.4 times the mass of the Sun), it will continue collapsing under its own gravity, forming a black hole.
Black holes are incredibly dense objects with a gravitational pull so strong that not even light can escape from them. They do not have a surface or a solid structure like stars do. Once a black hole forms, it remains a black hole unless it loses mass through processes like Hawking radiation, which is a theoretical phenomenon that causes black holes to slowly emit particles over time.
However, there is a theoretical concept called "black hole evaporation" proposed by physicist Stephen Hawking. According to this concept, black holes can slowly lose mass over an extremely long timescale through quantum effects. As they lose mass, their size decreases, and eventually, they may reach a point where they are no longer considered black holes but rather extremely dense objects known as "black hole remnants" or "micro black holes." These remnants are still not stars but rather remnants of the black hole's previous state.
To summarize, while black holes can lose mass over time, they do not regain their status as stars. They remain as black holes or, in the case of black hole evaporation, potentially evolve into remnants with different characteristics.