Use 'hasten' when emphasizing urgency and the importance of time in completing an action. We must hasten the release of the new product to beat our competitors.
Pro Tip 2/3
Deliberate Speed
'Hasten' often implies intentional action to increase speed, not a natural or automatic process. The onset of winter hastened the birds' migration.
Pro Tip 3/3
Negative Consequences
Sometimes 'hasten' indicates causing something negative to happen sooner, like failure or demise. Ignoring the symptoms might hasten serious health issues.