Carlos has two children, Maria and Jose. Maria is married to Luis, and they have a son named Roberto. Esperanza is Carlos' wife and the grandmother of Sofia, who is Jose's only daughter. How are Luis and Sofia related to Esperanza and Roberto, respectively? Is Luis Carlos' son?
Respond very briefly.
Luis is married to Maria, who is Carlos' daughter, making Luis Carlos' son-in-law and Esperanza's son-in-law as well. Since Esperanza is married to Carlos, any of Carlos' children's spouses would also be considered her children-in-law. Therefore, Luis is Esperanza's son-in-law.

Sofia is Jose's daughter, and since Jose is Maria's brother, his daughter Sofia is the cousin of Maria's son, Roberto. Thus, Sofia is Roberto's first cousin.

Luis is not Carlos' son; he is Carlos' son-in-law, because he is married to Carlos' daughter, Maria. Carlos' son is Jose, not Luis.