> Languages take immense effort to learn, and people will only learn
> them if it's socially or economically inescapable. [Zompist][1]

Choose a combination of stick and carrot depending of how powerfull the government is and how dirty they wanna play:


1. Train and license teachers that will strictly teach in the conlang. 

2. Open schools that will educate students in the conlang.

3. Make knowing conlang obligatory for anyone who wants government job. Most of the people are risk averse and steady government paycheck is the only ticket to middle class. 

4. Make all official documents & legal contracts only in the conlang. 

5. Organize campaign of eradication of illiteracy, see [Likbez][2] . Where illiterate means can't use the conlang.

6. All schools must use the conlang as language of instruction. Ban those who won't. 

7. Propagate the glory of the official language.

8. Make all the print (newspapers, books) conlang only.

9. Make all radio & tv programs conlang only.

10. Invest in conlang literature (prose, poetry, dramas).

11. Invest in conlang music, radio dramas, movies.

12. Mock all those who refuse to learn the conlang as backward, stupid or enemy of the state. See supression of French regional dialects as an [example][3]


If you prefer to use national pride take a look at [Revival][4] of the [Hebrew language][5] its not a conlang, but its the only language that was brought from sacred language to a spoken and written language used for daily life.


  [1]: http://www.zompist.com/whylang.html
  [2]: https://en.wikipedia.org/wiki/Likbez
  [3]: http://www.france-property-and-information.com/dialects_of_the_french_language.htm
  [4]: https://infogalactic.com/info/Revival_of_the_Hebrew_language
  [5]: http://www.jpost.com/Jewish-World/Jewish-News/This-week-in-history-Revival-of-the-Hebrew-language