English speakers are often found asking for the difference(s) between the words ‘till’ and ‘until’. The fact of the matter is, however, that when ‘till’ acts as a preposition or conjunction, there is no difference between the two words.
To clarify, ‘till’ has multiple meanings: it works as a noun, verb, preposition and conjunction. ‘Until’, on the other hand, works only as a preposition and a conjunction; in these capacities, both words mean exactly the same thing and are thus entirely interchangeable. ‘Till’ is actually the older word. ‘Until’ was formed by the addition to it of the prefix ‘un-’, meaning ‘up to’. Today, as the first word in a sentence, ‘until’ is generally preferred.