When moro follows a property item such as langa 'long', it functions as a pass/exceed verb that marks the standard. The standard cannot be omitted. In the construction ju langa, langa can be assigned a nominal reading ('your tallness') as well as a predicative adjective status ('you are tall'). When moro preceeds the property item, several readings are possible. Here it can be a verb marked by the imperfective aspect marker de, or it can be a degree word that modifies langa. In the latter case de is a copula.
Source: Schumann 1783: 98