Playing a part can be used interchangeably with other expressions to convey the same idea in different ways. For example, "taking on a role," "assuming a character," and "acting a part" all mean the same thing. Similarly, "playing a character" and "portraying a role" are also synonymous. "Playing a part" can also be replaced with the phrases "performing a role," "acting out a part," or "enacting a character." Sometimes, "playing a part" can have a negative connotation, such as pretending or not being genuine. In this case, phrases like "putting on a persona" or "presenting a facade" could be used instead.