When questioning if something is true or not, "is that a fact?" isn't the only phrase you can use. There are plenty of synonyms and alternative ways to ask for clarification or truthfulness. Some other phrases that you can use include "are you sure that's true?" or "can you confirm that for me?" Additionally, you can ask "is it accurate to say that...?" or "can you validate that statement?" It's important to make sure that the information stated is accurate, and asking for further clarification or validation can help ensure that you're receiving the correct information.