The Assistant Minister responsible for Culture has defended plans to spend £1.5 million promoting Jèrriais.
Deputy Montfort Tadier says the native language is part of what makes Jersey unique, and it should be protected to keep the island from becoming like a generic English town.
The money - set aside in the Government Plan - will be used over the next four years to teach the island's native language in schools and promote it through the Office du Jèrriais.
A proposition from St Saviour Deputy, Jeremy Maçon, was also passed - formally adopting the language on future government stationery and signage.
Deputy Tadier says the government needs to spend at least £375,000 to safeguard the future of the language, which would be a small fraction of what is currently being spent every year.

Simon Calder on drone havoc: 'Deeply troubling that somebody thought this would be a good idea'
Roll of Honour unveiled at Charing Cross
Consultation on plans to admit girls into Victoria College sixth form
Call for Jersey to break down stigma surrounding fertility struggles
Airport drones: 'Every available avenue is being pursued'
Jersey working with UK and specialist agencies after drones disrupt flights again
Flights affected by drones for second night running
Appeal after drone reports near Jersey Airport