垃垃

Etymology
First syllable from a lenited form of  which later experienced glottalization and potential assimilation with, mainly in circa 19th century Shanghai.

The second syllable is likely cognate with the personal pronoun pluralizer in e.g. Shanghainese, which may in itself be a lenited non-checked tone variant of according to  and. Compare.

Alternatively this might be a reduplicated form of.

The aspect marker senses are part of a commonplace semantic derivation in Wu and some of Gan, whereby preposition-demonstrative phrases come to be grammaticalized as stative verb markers.

Verb

 * 1)  to be at; to be in

Preposition

 * 1)  at; in

Adverb

 * 1)  be ...-ing; in the middle of doing something