'worker's' originates from English, specifically the word 'worker', where 'work' meant 'activity, labor' and the suffix '-er' meant 'one who does (something)'; the apostrophe-s is the possessive inflection.

'worker' was formed in Middle English from 'work' + the agentive suffix '-er'; the possessive suffix 's' was later attached to indicate ownership, producing forms such as 'worker's'.

Initially, 'worker' meant 'one who works'; over time the form 'worker's' has been used grammatically to indicate possession ('belonging to the worker') and colloquially as a contraction ('worker is' / 'worker has').