In that case you ought to be reframing the problem, answering a different question that you are comfortable giving a definite yes or no too. For example, Them

In that case you ought to be reframing the problem, answering a different question that you are comfortable giving a definite yes or no too. For example, Them: “Will you do x thing for me by year end?” You: “Are you actually trying to solve y problem? What if I refer you to Z person by end of day? Or start by bringing you some research around X by end of month?” Tbh the same applies to business not just personal