"The family works in the fields."
Translation:La famiglia lavora nei campi.
There is some debate about how to handle what are known as collective nouns. They are singular, but consist of a group. Another example is audience. You could say, "The audience here are sitting on their hands" (That's from Evita) In British English, the use of the plural verb (The family are always fighting among themselves) is more common. The context is the key. If the family "are" fighting, then the individuals in that group are fighting. So, it's actually more like "The family [members] are fighting among themselves." The individual members of the group will determine what verb to use. I used "lavorano". I think it COULD be correct.
"The family is ..." and "The family are ..." in English are pretty much governed these days by common usage, and the individual's preference, more than rules. I was educated with strict grammar rules about these things, but I see different usage to mine all the time in respectable sources. Things are loosening.
Because it is 'i campi', it must be 'nei campi' ;-)