I had a grand time at a family reunion last weekend. I’ve been thinking about the words we use in English to talk about the people who become our family by marriage. For example, think about your brother-in-law or your sister-in-law. (You can’t think about mine: I’m an only child married to an only child. If you don’t have any either, let’s think about the Weasleys. They have plenty.)

“Brother-in-law” means both “sibling’s husband” and “spouse’s brother.” Why don’t we have different words for those two relationships?

Step down a generation, and the linguistic differences disappear even more. English has the old terms “aunt-by-marriage” and “uncle-by-marriage,” but they aren’t in common use. When I was young, my parents’ siblings and their spouses were all just “Aunt” and “Uncle.” Certainly I knew the difference; I adored stories about “When Mommy Was A Little Girl.” I knew which aunts and uncles appeared in those stories as Mommy’s sisters and brothers. It never struck me as odd that the others were Mommy’s “in-laws” but they were just my aunts and uncles too.

When I was a teenager, one of my aunts by marriage brought her niece to a family reunion. It was a little strange for me to realize that she had her own whole family too, in which my own uncle was the latecomer. Her niece is about my age, and we hit it off.

“So your aunt married my uncle: does that make us anything?” I asked her. We decided that it probably didn’t make us anything … except friends.