Here's how you can change your language settings on a chromebook.
1. Move your mouse pointer to the lower right hand side of the screen, and click on the time clock.
2. Select the settings icon.
3. Select advanced settings.
4. In the Languages and Input section, select language
5. Select the language that you want to use on the chromebook.
6. If you don't see the language that you want to use, select on "Add Languages". Add the one that you'd like to use.
7. Select "Display Chrome OS in this language".
From Spanish to English:
Steps 1 and 2 are the same.
3. Select advance settings (configuracion avanzada)
8. Under "Idiomas y entradas", select Language (Idioma)
9. Select the language that you want to use (ingles - Estados Unidos)
You will then select the checkbox for "mostrar el so chromo en este idioma".
Restart the machine. Your language should be back to english.