In addition to what the handsome Eliot says, though as the first word in a sentence 'until' is usually preferred: Example. Until you get that essay written, don't even think about going to the movies. 'Till' is actually the older word, with 'until' having been formed by the addition to it of the prefix un-, meaning "up to" ... Although 'til is now nonstandard, 'til is sometimes used in this way and is considered acceptable, though it is etymologically incorrect.

They're the same word.

Thanks a lot )))