SOURCE: create . piktochart . com/output/6651983-hmong-language
Although the official language of Laos is Lao, only around half of the population can actually speak it.
The average tourist will have little need to be aware of the language, but if you plan to live and work as an English language teacher in Laos you are very likely to find yourself teaching native Hmong speakers at some stage.
The remainder of the people, particularly those outside of the main cities, speaks an ethic language such as Hmong.
This guide to basic Hmong might be a useful tool to have in your bag if you want to practice some simple words and phrases before or during your stay in Laos.