Your great aunt's husband is your great uncle, but his siblings and their children and grand children are not related to you. The grandsons of your great aunt's husband's siblings are his great nephews (not related to you).
On the other hand, all of your great aunt's great nephews are also her husband's great nephews. These great nephews are the grandchildren of your great aunt's siblings. They are you (if you are a boy), your brothers (if you have any), your male first cousins and your male second cousins on whatever side of your family your great aunt is on.
Your great aunt's husband is your great uncle.
All great aunts are married to great uncles. The child of a great aunt and great uncle is the first cousin of one of your parents, and your first cousin, once removed.
Your great uncle's wife is your great aunt.
yes
great nephew
yes
The possessive form for the plural noun great aunts is great aunts'.Example: My three great aunts' house is a great place to visit.
There are Aunts, great aunts, great-great aunts, et al. A second aunt would be if you have two aunts and you prefer one over the other. But no there isn't.
The cousins of your in-laws are not related to you and neither are their parents. However, the parents of your spouse's first cousins are your spouse's aunts and uncles, and thus your children's great aunts and great uncles.
If your great uncle married into your family some of his nieces and nephews are your aunts or uncles (or your parent) and some are not related to you at all.
Your great aunt is the sister of one of your grandparents. The wife of one of your grand parent's brothers is your great aunt by marriage. Another way to look at it is that your great aunts are the aunts of one of your parents.
Your great grandparents' brothers and sisters are your great great aunts and uncles.
First cousins, twice removed. Aunts daughter is your cousin. Aunts daughters daughter is cousin once removed Aunts daughters daughters daughter is cousin twice removed.
Great aunt.
No, great-aunts' is the possessive form of the pluralnoun, indicating that something belongs to two or more great-aunts.Example: Both of my great-aunts' birthdays are the same day.The possessive of the singular noun great-aunt is great-aunt's.Example: My great-aunt's birthday is on Friday.