The Spanish verb 'comprar' (to buy) comes from the Latin word 'comparare', which meant 'to prepare together' or 'to acquire'. This Latin word was formed by combining two elements: the prefix 'con-' meaning 'together, with' and the verb 'parare' meaning 'to prepare or arrange'. Over time, the meaning evolved from the idea of 'preparing or arranging together' to specifically refer to the act of acquiring or purchasing something.

Some related Spanish words include 'preparar' (to prepare), which comes from the same Latin root 'parare'. You can see how both 'comprar' and 'preparar' share the idea of arranging or getting something ready, though 'comprar' specifically evolved to mean acquiring something through purchase.

Several English words share the same Latin origins as 'comprar'. The word 'compare' comes directly from the same Latin word 'comparare', though it retained more of the original sense of 'putting things together' for examination. The word 'prepare' is also related, coming from Latin 'parare'. Even 'parade' is distantly related, as it originally referred to preparing or arranging things for display.