forms of the verb a fi are derived from : sunt, ești, , suntem, sunteți, sunt in the present tense and eram, erai, era, eram, erați, erau in the imperfect.A sta (stare) ( → sta) means "to stay" or even "to stand", "to stand still" or "to dwell/reside" e.g. a sta in picioare, as in Italian stare in piedi or unde stai? – "where do you live/reside?" A fi Sources of the Romance copula † Demonstratives used when necessary. For information on the morphological evolution of the Romance copula, see Romance verbs. See also Verb Copula Indo-European copula Grammatical conjugation Latin Latin grammar Latin declension Latin conjugation Vulgar Latin Romance languages Catalan language Catalan grammar Conjugation of auxiliary Catalan verbs Conjugation of regular Catalan verbs French language French grammar French verbs French conjugation Italian language Italian grammar Italian verbs Portuguese language Portuguese grammar Portuguese conjugation Romanian language Romanian grammar Romanian verbs Romansh language Sicilian language Spanish language Spanish grammar Spanish conjugation Spanish irregular verbs Spanish verbs Romance verbs Romance-based Creole languages French-based creole languages Portuguese Creole Cape Verdean Creole Spanish-based creole languages References Notes Bibliography Williams, E.B. From Latin to Portuguese Machado, J.P. Dicionário Etimológico da Língua Portuguesa'' Further reading PDF documents, mainly on the Spanish copula The Acquisition of the Verbs Ser and Estar in Undergraduate Students (in the US) Acquisition of copulas ser and estar in Spanish: learning lexico-semantics, syntax and discourse Grammaticalization of ser and estar in Romance languages Indo-European linguistics Romance languages Strukturverben_(spanisch)