ago

The word 'ago' originates from the Middle English 'agon', the past participle of 'agon', meaning 'to go away, to pass'. This verb itself stems from Old English 'āgān', a compound of the intensive prefix 'ā-' (meaning 'away', 'from') and 'gān' (meaning 'to go'). The literal sense is thus 'gone away, passed by'. Over time, this participial form was reanalyzed as an adverb, specifically used to indicate elapsed time, shifting from the concrete action of departing to the abstract concept of time having passed. Its modern function, always placed after a time expression, solidifies its role as a marker of past duration.

The word 'ago' is a simplex word derived from a Middle English past participle.