Old Chinese had two families of negatives starting with *p- and *m-, respectively. Northern and Central varieties tend to use a word from the first family, cognate with Beijing "pu"5 , as the ordinary negator. A word from the second family is used as an existential negator 'have not', as in Beijing "mei"2 and Shanghai "m"2. In Mandarin varieties this word is also used for 'not yet', whereas in Wu and other groups a different form is typically used. In Southern varieties, negators tend to come from the second family. The ordinary negators in these varieties are all derived from a syllabic nasal *m̩, though it has a level tone in Hakka and Yue and a rising tone in Min. Existential negators derive from a proto-form *mau, though again the tonal category varies between groups.