In this paper we focus on the functions of the future participle in Goan Konkani. In addition to the more-or-less expected functions of a future participle, such as nominal attribution or marking a future or modal predicate in various subordinate and main clauses, the future participle in Konkani can also mark main predicates with a past habitual interpretation in a construction which we refer to as the “promise-construction”, as it is only found with a small class of main predicates such as promise, intend, think, etc., which take an object complement clause. We argue that the future participle originally denoted an atemporal event and later came to include habitual events with any temporal value (past, present or future), and that this has since grammaticalized with exclusively past habitual temporal reference in this one construction, as this was likely the most common environment in which habitual events of this semantic class of verbs occur.