It might seem like a simple tool that can help you figure out whether a job candidate is telling the truth, but a conversation about references can quickly spell legal trouble for an employer. Don’t worry. We have you covered. But do you know what questions to ask references? Checking in with a reference is a crucial part in vetting a candidate for employment. What Can Be Asked on Personal Reference Calls?. Feel free to ask any questions that relate to the job, but remember that any questions about protected classes (race, age, sex, etc.) By talking to an individual’s personal and professional references, you have the opportunity to gather more information about the person and his/her work ethic. References can provide valuable insight into a candidate’s work style, attitude, successes, and failures in the past. In the world of business, references can be a touchy subject. that are illegal to ask in an interview are also off limits during a reference check. Here’s our list of the 10 of the best questions to ask when checking references: Then it’s time to dive into the questions.