Um especificador aí

in this article we deal with a type of aí which seems to add a specificity feature to indefinite noun phrases, similar to the linguistic item certo. based on analyses of the english certain carried out by hintikka (1986) and en？ (1991), we compare sentences with aí and certo. we aim to demonstrate that such specificity items show equivalence of semantic features, but tend to lead to different conversational implicatures.