confine to ?

Yes Ara, I'd say so

Gonna ask my Better Half, who as you know is much smarter than I, what she thinks, but at the moment she's watching live tv

Thanks for using my abbr; others denounce me for it

"Collo" is not a genuine abbreviation, it's something journalists made up (or so Dale says). Journalists are the bottom feeders of the English language.

The students are confined to the building until the rioters outside withdraw.

That is a perfectly acceptable and idiomatic sentence, Arafat, you did well. (You misspelled "building," but i'm assuming that was a typographical error.)

My Better Half agrees

There is something you need to understand, Arfat. A colloquy is a conversation, so colloquial means as used in conversation. Conversational usages are not, however, necessarily going to be grammatically correct. For example, someone might say: "That sounds like fun--you and me should go to that show." That would be colloquial English, but it would not be correct English. The correct construction would be "you and I should go to that show." That something is colloquial does not recommend it to the learner of the English language.

Yes, no, that's right S., it's not

Not other journs, just I apparently

Thank you for you concrete explanation , i was so busy for a competition these days , so had no time to view the answers .Thanks again . i will take notice on the usage of colloquial english and formal english.