Prefix · through / completely / intensively
Signals through, completely, or with intensity: perfect, permanent, persist, pervade, persuade.
Written by Bryan López, English teacher · Updated
Per- comes from Latin "per" (through, completely, with intensity) and signals that something goes all the way through or is completed totally: perfect = done completely (per = completely + fect = done); permanent = lasting through all time; persist = hold firm through difficulties; permeate = penetrate through something; pervade = spread through an entire space.
Per- often functions as an intensifier, adding the sense of "totally" or "completely": perplex = confuse completely; pervert = twist completely in the wrong direction; perfect = finished completely; pernicious = harmful in a way that penetrates to the deepest level; perspire = to breathe through the pores (sweat). The idea of going through or completing is always present.
Attaches to nouns, adjectives, and verbs. Identical in Spanish and English:
Pronunciation: /pɜːr/. Identical in Spanish and English. Different from "pre-" (before) and "pro-" (in favour of).
per-/pɜːr/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
As an adjective: "PER-fect" (stress on first syllable) = having no flaws. As a verb: "per-FECT" (stress on second syllable) = to make flawless or improve until perfect. "She has a perfect score" (adj) vs "She is perfecting her technique" (verb). This stress-shift pattern is common in two-syllable English words.
"Persuade" means to convince through reasons, arguments, or emotional appeal: "She persuaded him by explaining all the benefits." If force is used, it is "coercion" ("coerce," "force," "compel"), not persuasion. Persuasion respects the other person's will; coercion overrides it.
A trick to remember it
Per- = "through" or "completely": perfect = completely done, permanent = lasting all the way through time, persist = hold firm all the way through difficulty, pervade = spread completely through a space. Identical in Spanish. Note: "perfect" shifts stress as a verb: "PER-fect" (adjective) vs "per-FECT" (verb = to make perfect).
Exercise 1 · Form the word
Exercise 2 · Pick the right one
"Despite three consecutive failures, she continued to ___ with her research until finally achieving a breakthrough."
Exercise 3 · Pick the right one
How does the pronunciation of "perfect" change when used as an adjective versus a verb?
The prefix per- signals through, completely, or with intensity: perfect, permanent, persist, pervade, persuade. In Spanish it usually maps to per-.
The prefix per- is pronounced /pɜːr/. For example, "perfect".
"fect" becomes "perfect". It is a typical example of the per- prefix.
Signals around or surrounding something: circumference, circumstance, circumnavigate, circumspect.
Signals support for something or forward movement: progress, promote, provide, pro-democracy.
Signals crossing, transformation, or movement through: transport, transform, translate, transfer.
un-, re-, pre-, dis-, over-, in-... every beginning you need to unlock thousands of English words at once.