You may have heard (or read about) different formulas used by effective communicators. The 'uh-huh', nodding the head, 'I see'. There are numerous suggestions on practising 'active listening', 'reflective listening'...it can get really confusing.
But it doesn't have to be this complicated.
Imagine this scenario: a patient is complaining about everything, and you are caught in the middle of this seemingly unending discourse. Or, a colleague is ranting and you feel you are expected to contribute to this rant, or at least show some 'support' and agree. There is one sentence that you can use, and it's simple: "I hear you".
The reason this sentence is so effective is that it still keeps you in a balanced position, that of neutrality. You neither agree, nor disagree. You show that you are listening, empathizing. From my experience, if you say this sentence enough times, on a sincere tone (not like a robot!), the other will slowly run out of gas and gain insight that they are in fact complaining. This is one of my favourite formulas. Try it out!?