How to call your great aunt? For example, if the great aunt's name is Mari, is she called 'Great aunt Mari, or 'Aunt Mari' or just 'Mari'?
It often depends on the context.
If you asked me, "How are you related to Mari?" then, for the sake of precision, I would answer:
She is my great aunt.
However, in casual conversation, the great is often omitted, so I might say:
I need to leave work early today. My aunt Mari is coming to visit.
even though she's really my great aunt.
If I'm talking to people who already know that Mari is my aunt, the title is often omitted. So, for example, if I was talking to my mother on the phone, I could say:
Mari called me last week.
In other words, it's not considered improper to refer to her without the title of "aunt."
Through my childhood and into my adulthood, my cousins and I would omit the word "great" when talking about our great uncles. They were simply "Uncle Bobby" and "Uncle Jimmy."
Some families might change the convention to suit their needs, though. For example, suppose you had an uncle and a great uncle who were both named David. Your family might refer to them as "your uncle Dave" and "your great uncle Dave" just to avoid ambiguity.