Estonian conditional clauses have previously been divided into two clear-cut groups: real and unreal, with indicative and conditional main verbs of conditional clauses, respectively. This article defends the view that it is a question of the degree of hypotheticality that a sentence conveys, and it treats hypotheticality as a continuum that includes groups of linguistic forms, which have a relatively clear core and are separated by fuzzy transition areas. Secondly, the article concentrates on the relationship between Estonian conditional clauses and temporal clauses. As these clause types have the same marker (kui), the article discusses whether it is always possible to distinguish between these two clauses and which factors are relevant for determining whether the clause is a temporal or conditional one. Thirdly, the relationship between Estonian conditional and concessive clauses is under consideration, focusing particularly on Estonian scalar concessive conditional clauses.