In most cases people behaves as a plural, as in People are funny; you never know what they will do. When people means "a group of human beings sharing one specific nationality, culture, or language," however, it is regarded as a singular and when used in the plural, takes an s plural ending: a Native American people of the Southwest, one of several such peoples noted for their peaceableness. The possessive of people is formed by adding an apostrophe + s if one people is stipulated: the people's choice of a new president. If many peoples are stipulated, the possessive is formed by adding an apostrophe after the s: various Caribbean peoples' representatives at the conference. People is the preferred form in designating human beings in the plural generally: Thousands of people [not persons] jammed the stadium.What on earth will people [not persons] think if you do that? Use persons only in certain narrow, typically legalistic or otherwise official, contexts: the Bureau of Missing Persons;the arrest of three suspicious persons loitering outside the White House gates.