Among the typologically agglutinative Finno-Ugric languages, Estonian is in many ways exceptional since it has developed a long way towards the analytic type. One indicator of this is the extensive use of particles and adverbs to indicate grammatical relations such as aspect. Our paper discusses, in a Cognitive Grammar framework, the grammatical functions of the adverb välja ‘out’, which is originally an illative (‘into’) case form of the lexical noun väli ‘field’. Our study shows how the meanings evolve along a continuum from concrete senses to more abstract ones, and we set out to find motivations for the development. The form välja has developed numerous usages as an adverb and a verb particle. Its concrete spatial meaning is that of indicating a relation where a mover exits a (typically three-dimensional) container and moves from its inside to its outside. The abstract functions of this multi-functional gram include the following ones: 1) a change in the cognitive state of an animate participant (e.g., as the result of acquiring information), 2) changes-of-state metaphorically represented as motion out of a container, 3) terminative direction or distance (‘all the way to X’) and 4) perfective aspect. We argue that a crucial factor in the development of these functions is the placement of the conceptualizer's viewpoint either inside or outside the container which the mover exits. A viewpoint outside the container means that in the initial configuration the mover is hidden from the conceptualizer's view, and when exiting the container it becomes accessible to the conceptualizer. This meaning motivates abstract functions where välja indicates incipient availability or accessibility of the mover. On the other hand, a viewpoint situated inside the container results in the meaning where the mover (that exits the container) escapes from the conceptualizer's view, or, in abstract expressions, its cognitive dominion. This motivates the use of the gram in many expressions of a change of state, and in particular builds a link to its aspectual functions where it indicates the spatiotemporal extent of an event or an entity by measuring the distance from the starting point of such (concrete or metaphorical) motion.