This one is a very commonly made mistake. The basic thing that you need to remember here is that you need to use a singular verb with a singular subject and a plural verb with a plural subject. Going by that rule, people here is a plural subject (or plural noun) and say is the plural verb. read more
‘People say’ is correct, because people refers to a group of persons. Example :- People says that Django Unchained is a good movie. People say that Django Unchained is a good movie. The second one sounds more intuitive and meaningful. read more
People says' is incorrect, while 'people say' is correct. I found most of this on Google: 'People' is used as the plural of 'person'. So 'people' = 'persons' It is a plural count noun and takes a plural verb. It never has an -s ending because it is already plural. "People" is a collective noun or group noun. read more
In the sentence "The people say they want more money," the word "people" is referring to more than one person. But, in the sentence "The class says it wants less work" class is used as one thing, though there may be multiple people in the class. read more