Here are hundreds of one-liners and longer jokes on subjects including animals, families, food and drink, dating, and education. This collection of clean jokes for adults (nothing off-color or offensive) is sure to prompt chuckles, giggles, and full belly laughs. A linguistics professor was lecturing his class. "In English a double negative forms a positive. In some languages, however, such as Russian, a double negative is still a negative. But there is no language where a double positive can form a negative." A student at the back called out: "Yeah, right."