For example if the other party says: “ You swore at me, pushed me and walked away” and you believe that this is incorrect you can attack the party: “ you are a liar!” or you can attack the problem: “ My recollection is……….. I feel upset when you say that happened when I believe it is not true.“ An attack on the person is likely to force the other party to get defensive and possibly attack back, or close down. A frank but respectful assertion of the problem on the other hand leaves the other party more comfortable reconsidering and at least hearing your view. It can be helpful to begin : “When you………. I feel……….”
Note that recollections are often distorted by overloaded emotions or filtered through powerful belief systems or blurred by substance abuse or other memory inadequacy and understood through widely differing perspectives. Recollections can often differ markedly yet be nevertheless genuine.

Start with “I”.
Use personalised phrases such as “ I believe” or “ I think” to convey your understanding. It gives more space to allow the other party to take a different point of view or to agree with you without loosing face , as you are not stating your belief or opinion as a fact or an absolute.

No fixed rules
The above guidelines are not cast in stone. There are occasions in the spontaneity of relationships where for example instantaneous anger can be a circuit breaker. At times it can be important to describe the anger you feel and why.