If you would like to learn Spanish I can recommend you Spanish School Sol Latino in Quetzaltenango.
I stayed here for 3 weeks and I would have loved to stay longer! In January I started my journey through Central America in Guatemala. Because I only studied Spanish a long while ago at my University I needed a fresh up course Spanish, so I took classes at Sol Latino. They responded my questions by e-mail fast and professional which made me decide to study at this school. I also heard of other travellers that Quetzaltenango would be a better place to learn Spanish then in Antigua and San Predro and they were right! The ambient in Quetzaltenango is very different because there are less tourists and most people in Quetzaltenango are here to learn Spanish and/or to volunteer. The locals hardly speak any English and many tourists want to speak Spanish as much as possible.
You begin your week at Sol Latino with a short presentation of all the students and teachers. Then you have to make a test to determine your Spanish level. The teacher then makes a study plan for the week with also your own input. In general classes start with a small conversation, then you are going to discuss your homework, new grammar/vocabulary and you do some exercises. Sometimes we also played Scrabble (in Spanish) by the end of the class which is also a fun way of practicing Spanish.
At the last day of every student they have cake and there's a small graduation ceremony including diplomas!