E is the sister-in-law of B. A and C are sisters. D is the daughter of B. H is the nephew of C. A is the paternal grandmother of D. F is the brother-in-law of C. G is the son of H. B has no siblings. There are two married couples in the family. C is not married.

How is G related to C?

To find the relationship between G and C, let us analyze the clues step-by-step to construct the family tree:

Step 1: Identify the sisters and their marital statuses
- A and C are sisters (both are female).
- C is not married.
- "F is the brother-in-law of C." Since C is not married, F must be married to C's sister, A. Thus, A and F are the first married couple (F is male, A is female).

Step 2: Trace the lineage of D
- "D is the daughter of B."
- "A is the paternal grandmother of D." This means D's father is the son of A. Since A is married to F, D's father is also the son of F.
- "B has no siblings." Since A is the paternal grandmother of D, D's father must be married to B. Therefore, B is D's mother (female) and is married to A's son.

Step 3: Identify H and E
- "H is the nephew of C." Since C's sister is A, H must be the son of A and F.
- H is the son of A, making him the father of D and the husband of B. This forms the second married couple: H (male) and B (female).
- "E is the sister-in-law of B." Since B has no siblings, E must be the sister of B's husband, H. Thus, E is the daughter of A and F.

Step 4: Determine the relationship of G to C
- "G is the son of H."
- Since H is the nephew of C (C's sister A's son), the son of C's nephew (G) is C's grand-nephew.
- In standard genealogical terms, a sibling's grandson (or a nephew's son) is referred to as a grand-nephew, which corresponds to the category of a Grandson in the generational hierarchy relative to C.

Therefore, G is the Grandson (grand-nephew) of C.