How to keep people interested in learning english?

Okay so next week my mother in law and I are volunteering the teach immagrants to speak english I live in texas so most of them will be mexican immagrants I learned that so many of them will eventually drop and and I dont want that to happen soo if you...

can give me some good ideas on how to keep them interested and wanting to come back..thanks guys..

Well, people should be aware that immigration is not ever easy - especially if you are not familiar with the dominant language of a country.
Not only is it our dominant language (note: the USA does not have an OFFICIAL language - rather, English is a DOMINANT language), but it is also a dominant language throughout the entire world.
Also, it has plenty of cognates with Spanish. Teaching true cognates definitely helps people stay motivated to learn a language because it helps them be able to quickly identify and translate phrases and words.

And I hate to say it, but immigration is still an issue in the United States so the more they're able to prove them wrong, the better. Because it's difficult to get a job here (employers often think applicants want to work because they need visa sponsorship, not because they want to actually work there), knowing the dominant language will DEFINITELY help - especially because so many places now prefer bilingual speakers.

A hard transition in, but they will have a definite upperhand over the typical US citizen!

Best of luck!