pneuma

What it means

Pneuma covers a genuine range in Greek: the wind that moves the trees, the breath that leaves a dying man's body, the inner disposition of a person under strain, an unclean spirit that possesses someone, and the Spirit of God moving over creation or filling a believer. All of these are named by the same word, because Greek writers treated them as versions of one thing — invisible, moving, active, hard to pin down and impossible to hold still.

English has no equivalent this wide. Wind, breath, and spirit are three separate words with three separate registers, one meteorological, one physiological, one religious. A translator meeting pneuma has to decide, often with little help from the sentence itself, which English word the context calls for, and that decision fixes a meaning the Greek left open.

What English does with it

English translations sort pneuma into wind, breath, or Spirit, capitalizing the last when they judge God is meant. John 3:8 loses its wordplay this way: the same Greek word becomes a lowercase 'wind' and a capitalized 'Spirit' within one sentence. That capital letter is an editorial decision, not something present in the Greek text, which had no case system to mark the difference.

The common mistake

The common mistake is assuming pneuma always means the Holy Spirit whenever it appears in the New Testament. Often it just means ordinary breath, a gust of wind, someone's mood or inner state, or an evil spirit troubling a person. Reading 'Spirit' into every occurrence flattens a word that Greek kept deliberately broad.