世帯 and 世代: counting households and generations
Compare ten households and supplies distributed per household with a song enjoyed by parents and children and skills taught to a younger generation. Learn which unit 世帯 and 世代 identify.
世帯 counts households
世帯 (せたい) identifies a household. “この建物には十世帯が暮らしている。” (“Ten households live in this building.”) counts ten households living in the building. It gives no headcount for their members, so ten households cannot be converted into ten people.
“世帯ごとに防災用品を一つずつ配った。” (“We distributed one emergency supply to each household.”) makes each household the unit of distribution through 世帯ごとに. One supply was distributed to each household; the sentence does not say that every family member received one.
世代 identifies generations
世代 (せだい) means a generation. In “この歌は親子二世代にわたって親しまれている。” (“This song has been enjoyed by two generations, parents and children alike.”), 親子二世代 identifies parents and children as two generations. The song's appeal extends across them; this is not a count of two households.
In “職人は若い世代に伝統の技を教えている。” (“The artisan teaches traditional skills to a younger generation.”), the artisan teaches traditional skills to a younger generation. The focus is on the generation learning the skills, rather than households receiving distributed items.
Keep the counting unit with the context
十世帯 counts households, while 親子二世代 names parent and child generations. Both expressions include numbers, but the units measure different things and do not establish how many individual people are involved.
Look at what the sentence does with the group. Residence in a building and distribution per household point to 世帯. Parents and children enjoying a song or younger people learning skills point to 世代.
Does この建物には十世帯が暮らしている tell us that ten people live in the building?
Show the answer and why
No. 十世帯 means ten households, and the number of people in those households is not given. It also uses a different unit from the parent-and-child generations in 親子二世代.