Compound family terms.

virginia274Does it differ to say GRAND uncle/aunt or GREAT uncle/aunt?

'Grand' is wrong in my estimation.

Your great-uncle is your grandfather's brother.
Your great-nephew is your brother's grandson

I've always said "great" as well, but I understand that "grandnephew" and "grandniece" are becoming more popular since it's more analogous to "grandson" or "granddaughter."

I had a great aunt who decided she liked the sound of grand aunt better, so that's what we called her. The others were still called great aunt though.

There are only two citations each in the Corpus of Contemporary American English for grand uncle andgrand aunt.

In the Corpus of Historical American English, the figures are:

grand uncle: 36 - 1830s, 34; 1890s, 1; 1930s, 1.
Grand aunt: 6: 1840s, 3; 1880s, 1; 1970s, 2 -

fivejedjongrand uncle: 36 - 1830s, 34; 1890s, 1; 1930s, 1. Grand aunt: 6: 1840s, 3; 1880s, 1; 1970s, 2 -

Thank you for your precise reply but please tell me what are those numbers,I'm really confused!

virginia274fivejedjongrand uncle: 36 - 1830s, 34; 1890s, 1; 1930s, 1. Grand aunt: 6: 1840s, 3; 1880s, 1; 1970s, 2 -Thank you for your precise reply but please tell me what are those numbers,I'm really confused!

grand uncle: 36 - 1830s, 34; 1890s, 1; 1930s, 1.

There were, in total, 36 citations. 34 were from material written/published in th

So....
In everyday speaking or in exams if I use grand uncle is wrong?
Or It's just not common?

If you are talking with people who are really into genealogy, they may think you are using the better term.

Among regular folks, I'd wonder why you didn't use the more common "great" term but you would not be misunderstood.