Groups can merge with a local school joining them for a specified duration.  (e.g. Language, Geography, Social studies, culture etc).

Outside school time and during recreational breaks there are opportunities for visit nearby sights or spend tie sharing or competing with sports, arts or entertainment with the local students.

Some visitors like to arrange home stays
Some visitors seek a sports challenge
Some visitors like to entertain the locals
Some visitors employ local specialised teachers
Some visitors join current classes with small numbers 

(NOTES: Local schools frequently require 6 months advance notice for an international visiting groups. Exams times are generally not advisable for visits. Best plans are made when schools communicate directly.