Hmm. You *could* but the connotation (underlying meaning) is a little different depending on the sentence structure. 'My partner is called Jane' - This is a fact - her name is Jane. 'I call my partner Jane' - This may not be her real name, but it is what I *always* call her. Perhaps her name is January [which would be an awful name]. But it implies that she accepts the name-change. I call Jane my partner -- I refer to Jane as my partner In this case, both of these sentences would be the same. However, this sentence (specifically about partners) would be very odd sounding to a native speaker. It almost implies that *I* call her my partner, but *SHE* doesn't call me her partner. Often when 'call something X' and 'refer to something as X' are equivalent is when we're implying that it isn't the 'true' name, so we'd usually say in a casual conversation... I *like* to call her my partner. / I *like* to refer to her as my partner. In this case, the two would be identical.

to call X "Y" is usually the correct or official name. refer to X as "Y" is usually making some kind of substitution for the real name. For example, in publications where someone is talking about a real person they won't want to use the real name. So they might say: The patient, referred to as "John" experienced... However, the patient's name might be something entirely different. Another example, in contracts and legal documentation most people/companies will use a standard contract. In these contracts the company will need to talk about the person signing (signee) and the company. So the beginning of the contract might say something like: The signee, __(name)____, hereafter referred to as "Y".... and then the contract doesn't have to change anything when used for different people.

thank you! very interesting!

Thanks for the answer! I just wanted to clarify, are there any cases when these words are interchangeable? For example, in the sentense "people who are not married, usually refer to each over as "partners"". Is it ok here to replace "refer" with "call"?