The Spanish word 'imponible' meaning 'taxable' or 'imposable' has its roots in Latin. It combines the Latin prefix 'in-' meaning 'in, into' with the Latin verb 'ponere' meaning 'to put or place'. These elements merged to form the Latin verb 'imponere' meaning 'to place upon'. This evolved into the Spanish verb 'imponer' ('to impose'), and with the addition of the suffix '-ible' meaning 'able to be', it formed 'imponible' - literally meaning 'able to be imposed' and commonly used in the context of taxation.

Some simpler related Spanish words include 'poner' (to put/place), which is the basic form of the same verb without the 'im-' prefix. You might also recognize 'imponer' (to impose), which is more commonly used than 'imponible'. Other related words include 'posible' (possible) and 'puesta' (placement), all sharing the same Latin root of placing or putting something.

English speakers can connect 'imponible' to several familiar English words. Most obviously, it's related to 'impose' and 'imposable'. The same Latin roots also gave us words like 'position', 'pose', 'deposit', and 'compose' - all of which relate to the basic concept of placing or putting something. The '-ible' suffix works the same way in both languages, appearing in words like 'possible' and 'terrible'.