SIS biggest problem “students not speaking English during school time”

SIS biggest problem “students not speaking English during school time”
Right now in Saipan International School (SIS) the foreign students are speak their own language instead of English. SIS is the English school, so everyone require speak only English. The reason for that is because this school exists for helping the foreign students improve their speaking ability. Students must change their habit of speaking their own language or else the teachers and the headmaster will deal with it hardly.
the speaking other language than English is getting worse and worse, the school has came up with a lot of ways that they think it will help reduces the number of students speaking other language. Right now SIS has a lot of Korean students more than other, so most of them are speaking Korean instead of English. And second most is Chinese students speaking Chinese instead of English. Right now school is trying very hard to come up with new idea that will help those students to stop.
There are the reasons behind the idea of the school want students only speaking English. It is good for the students, itself. The parents are pay $500 every mount for their children to attend to this school for the purpose of they want their children to be good in speaking English, to learn the second language. Recently, teachers had came up with three ideas which are, once they catch students speaking other language than English that student must have weekend detention, but it got turn down by the headmaster. Second student must pay money if they were catch speaking other language, it also got turn down. But it not going to be stopping at this point, teachers will find some way to stop this problem. It not for them but they do this to help students, so students must change their behavior if they love their parents and themselves.