I'm not a native English speaker and here in Brazil we have the word "expectativa" as a noun.
The expectative in English is defined as an adjective: http://dictionary.reference.com/browse/expectative
But I haven't see yet the usage in this form, rather we see "expectation", which act as the Portuguese "expectativa" (expectation). We do have this word as adjective "expectante" as is the "expectant" in English, but not the "expectative" form.
So, in which case we use "expectative"?
EDITED: I've googled and found this one: http://www.newadvent.org/cathen/05712b.htm
An expectative, or an expectative grace, is the anticipatory grant of an ecclesiastical benefice, not vacant at the moment but which will become so, regularly, on the death of its present incumbent.
Expectative land rights, house consolidation and cemetery squatting: Some perspectives from Central Java
Can you clarify?