Learn English – How did we get both sub- and infra- prefixes

etymologylatinprefixes

It seems that both sub- and infra- are prefixes that mean "below", leading to their use in different words to provide a similar meaning. We even have some words that are the same apart from these prefixes whose meanings could conceivably be flipped, eg. subsonic and infrasonic, substructure and infrastructure.

Normally in cases like this, the prefixes come from different languages but in this case, they both etymologically come from Latin. How did this come to be? Why 2 different prefixes with the same meaning?

Best Answer

The OED says that "infra-" was not a common adjective prefix in Latin:

representing Latin infrā adv. and prep. ‘below, underneath, beneath’ (in medieval Latin also ‘within’), used in numerous recent formations, chiefly adjectival.

This use of infra- is scarcely a Latin one, though infrāforānus ‘situated beneath the forum’ occurs in an inscription (Lewis and Short), and infrāmūrāneus ‘lying within the walls’ in Gregory of Tours (Du Cange). Its recent employment is after the analogy of other prepositions; it is regularly opposed to supra-, sometimes to super-: the second element ought strictly to be one of Latin origin; but it is not always so.

It's not that uncommon for a language to have multiple prepositions with similar or overlapping meanings; e.g. English has both "under" (which is cognate with infra, actually) and "beneath", or "over" and "above".

Related Topic