The Spanish verb 'iniciar' (meaning 'to begin') comes from the Latin verb 'initiare' with the same meaning. This Latin word was derived from 'initium' meaning 'beginning', which itself came from the verb 'inire' meaning 'to enter' or 'to begin'. The Latin 'inire' was formed by combining two elements: the prefix 'in-' meaning 'into' and the verb 'ire' meaning 'to go'. So etymologically, the concept of beginning something was expressed through the idea of 'going into' or 'entering into' something new.

Some related Spanish words include 'inicio' (beginning, start), 'inicial' (initial), and 'iniciativa' (initiative). All these words share the same Latin root and maintain the core meaning related to beginnings or starting something.

English speakers can easily connect 'iniciar' with words like 'initial', 'initiate', and 'initiative', which all come from the same Latin source 'initium'. The connection is clear both in form and meaning, as all these words relate to beginnings or starting something new.