Prefix · below / inferior level
Signals position below or a lower level: subway, submarine, subtitle, subconscious.
Written by Bryan López, English teacher · Updated
Sub- comes from Latin "sub" (under, below) and signals a physically lower position or a lower hierarchical level: subway = a route below the ground; submarine = a vessel below the sea; subtitle = text below the image. The core idea is always "below" in a physical or hierarchical sense.
Sub- can also signal a level below the expected standard: substandard = below the required level; suboptimal = less than optimal; subconscious = below the level of conscious awareness. In this use, sub- signals that something does not reach the expected threshold.
Attaches to nouns and adjectives with no spelling change:
Sub- is identical in Spanish and English, making it very easy to recognise. Pronunciation: /sʌb/, with a short "u" as in "cup".
sub-/sʌb/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
"The suburbs" are the outer residential areas, away from the center. They are the opposite of "downtown." In American English, the suburb-vs-city distinction carries strong cultural meaning.
In Britain, "subway" can refer to a pedestrian underpass. The London metro is called "the Underground" or colloquially "the Tube."
A trick to remember it
Sub- is identical in Spanish and English and highly recognisable: subway, submarine, subtitle, subconscious, subtropical. Every time you see sub- at the start of a word, think "below" or "one level under."
Exercise 1 · Form the word
Exercise 2 · Pick the right one
"The quality of the materials in that building was completely ___ and failed every inspection."
Exercise 3 · Pick the right one
What is the difference between "subway" in American and British English?
The prefix sub- signals position below or a lower level: subway, submarine, subtitle, subconscious. In Spanish it usually maps to sub-.
The prefix sub- is pronounced /sʌb/. For example, "subway".
"way" becomes "subway". It is a typical example of the sub- prefix.
un-, re-, pre-, dis-, over-, in-... every beginning you need to unlock thousands of English words at once.