Prefix · against / opposition
Signals active opposition or protection: antibiotic, antivirus, antisocial, antidote.
Written by Bryan López, English teacher · Updated
Anti- expresses active opposition or protection against something. antibiotic = acts against bacteria; antivirus = protects against viruses; antisocial = goes against social norms. The core idea is always "against" or "protecting from" something specific.
Anti- implies active opposition; non- simply negates. An antimilitarist actively opposes militarism; a nonmilitary context simply is not military. Anti- implies a stance or an active struggle. It is the prefix of those who are fighting against, not simply those who are not something.
Attaches to nouns and adjectives. Modern English usually writes it without a hyphen:
Pronunciation: /ˈænti/ in British and formal American English; /ˈæntaɪ/ in casual American English. Both are widely accepted.
anti-/ˈænti/ or /ˈæntaɪ/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
In formal English, "antisocial behaviour" describes conduct harmful to society. In casual American use it may mean someone who prefers not to socialise, but the formal sense is stronger and used in legal contexts.
Spanish "antídoto" stresses the "i." English "antidote" stresses the first syllable: AN-ti-dote. The stress pattern differs.
A trick to remember it
Anti- is identical in Spanish and English: antibiotic = antibiótico, antivirus = antivirus, antidote = antídoto. If you know the Spanish anti- word, the English equivalent almost certainly exists and sounds very similar.
Exercise 1 · Form the word
Exercise 2 · Pick the right one
"An ___ is a substance that neutralises a poison or harmful effect in the body."
Exercise 3 · Pick the right one
What is the difference between "antisocial" and "unsociable"?
The prefix anti- signals active opposition or protection: antibiotic, antivirus, antisocial, antidote. In Spanish it usually maps to anti-.
The prefix anti- is pronounced /ˈænti/ or /ˈæntaɪ/. For example, "antibiotic".
"biotic" becomes "antibiotic". It is a typical example of the anti- prefix.
un-, re-, pre-, dis-, over-, in-... every beginning you need to unlock thousands of English words at once.