K introduces N to his friend, saying, “He is the husband of the granddaughter…

Concept

In a family-relation chain, begin with the speaker and resolve each phrase from the inside outward. Keep blood relations separate from relations created by marriage.

A person married to one’s sister is called a brother-in-law. This differs from a brother, nephew, or son-in-law because each follows a different generational or marital link.

Application

1. The father of K’s father is K’s paternal grandfather.

2. The stem specifies that the granddaughter is a child of K’s father. Because K is male and this child is female, she is K’s sister.

3. N is the husband of that granddaughter, so N is the husband of K’s sister.

Contrast

• Brother: a male sibling of K, involving no marriage link.

• Son-in-law: the husband of K’s daughter, one generation below K.

• Nephew: the son of K’s sibling, one generation below K.

• Brother-in-law: the husband of K’s sister, which is the relation formed here.

Cross-check and result

Reading the chain in reverse, K is a sibling of N’s wife. Therefore N’s relation to K is brother-in-law.