Can anyone explain the rules for using
1. "till" or "until" insentences
2. "while" or "whilst" in sentences.
you can use till and untill interchangebaly in both writing and speech, though as the first word in a sentence until is more common. eg. Untill you get that paper written, don't even think about going to the movies.
whilst means the same as while; the former is more formal, though.
Till but Until