The word "Jensson" is spelled with a "J" (Jɛnsən) and not a "Y" (Yɛnsən) because it comes from a Nordic or Scandinavian background. In these languages, the letter "J" is pronounced as more of a "Y" sound, so this spelling stays true to the origin of the name. Additionally, the double "S" (sən) at the end signifies that the name is a patronymic or a surname based on the name "Jens," which was likely the name of the person's father or male ancestor.