A root meaning “before / ahead”; in space it feels like “forward,” in time “first,” and in action “toward ~.” It is the ancestor of the prefixes pre-, pro-, and per, as seen in prelude (overture), property (property/wealth), and performance (execution). Furthermore, many core English words arose from it, such as for (“for; for the sake of”) and far (“far; distant”).

A root meaning “behind / again,” carrying a sense of looking back to the past or returning to the original state. From this came the re- series (return, refer, remain) and the retro- series (retrograde). From the sense of “repetition,” it can also have an intensifying effect on the original meaning.

A root meaning “to see,” which extends beyond mere sight to “to know” or “to understand.” It has yielded wise (intelligent), wit (wisdom), view, video, idea, and so on.

A root meaning “to stretch / to pull.” From this, the sense of “to keep / to maintain” expanded, leading to tend (incline), extend (stretch), contain (include), tenant (resident), and tone (tension).

A root meaning “to move in a straight line.” It expresses correctness and order, producing words such as right (correct), rule (rule), regal (royal), royal (royal/royal household), regular (regular), and director (director).

A root meaning “two.” It branched into two, twelve (“ten and two”), between (“between two points”), doubt (“to waver between two”), etc., expressing division or duality. Twilight (the time of dim light) is the “boundary of two” between day and night.

A root meaning “to observe / to see.” From Latin specere (“to see”) come aspect, respect, species, special. From Greek skopein (“to see”) comes -scope (as in telescope, microscope—the suffix for instruments of observation).

A root indicating “to think / the state of mind.” Besides mind, mental, and memory, it also gave rise to music and monster. It is also the etymon of the word “mania” (an enthusiast).

A root meaning “to speak / to declare.” From Latin fari (“to speak”) came fatum (“that which has been spoken = fate”), which gave rise to fate and fairy (goddess of fate → fairy). Confess and profess (“confession / declaration”) are of the same origin. From Greek phōnē (“voice”) come phone, phonetic, and symphony—words related to “voice / sound.”

A root meaning “to live.” It connects to Latin vivere (“to live”) and Greek bios (“life”). It produced vitamin, vivid (“lively”), biology, biography, and so on. Spanish viva is a greeting that celebrates long life, equivalent to the Japanese “banzai.”

A root meaning “head,” the source of head. Via Latin caput (“head”) it branched into capital (“capital city = the nation’s head”), captain (“one who is the head”), cabbage (“a vegetable like a round head”), etc. It also produced words denoting “things of importance,” such as cattle (cattle; originally meant property) and capital (capital/wealth).

A root meaning “to breathe.” It branches to Latin anima (“breath; soul”) and Greek anemos (“wind”). It connects to animal (“a breathing/living being”), animate (“to breathe life into”), and unanimous (“of one breath = unanimous”).

It means knee, or more broadly an angle. Through Proto-Germanic it is the source of knee (knee). Via Greek it branched into polygon (“many-angled figure”), diagonal (“diagonal line”), and pentagon (“five-angled figure”).