Prophecy vs. prophesy: telling the noun from the verb

The short answer

Prophecy and prophesy are related words that split neatly along one line: prophecy is a noun, and prophesy is a verb. A prophecy is the prediction itself, the statement about what will happen. To prophesy is to make that statement, to foretell an event before it happens. Keeping the parts of speech straight is the fastest way to choose the right spelling every time.

• Prophecy: a noun, meaning a prediction
• Prophesy: a verb, meaning to predict

What each word means

A prophecy is a statement, often religious or mystical, about a future event. The ancient prophecy warned of a great flood. Prophesy is the action of making such a statement: the oracle would prophesy disaster whenever the omens turned dark. Note the pronunciation difference too: prophecy ends with a soft "see" sound, while prophesy ends with a "sigh" sound, which can help you hear which one you mean before you write it.

This distinction matters most in formal or academic writing, where mixing up a noun and a verb reads as a clear error rather than a style choice. In casual speech, people sometimes let the sounds blur together, but published writing, essays, and any assignment that will be graded should keep the two words strictly separate. When in doubt, try building a full sentence around the word: if it needs an object like "the future," you likely need the verb prophesy.

Correct and incorrect examples

Correct: the prophet's prophecy came true within a year. Correct: few people believed she could prophesy the market crash. Not: the prophet's prophesy came true within a year, since prophesy is a verb, not a noun. Not: few people believed she could prophecy the market crash, since prophecy cannot act as a verb in standard usage.

A useful test is to see whether the word is doing something or naming something. In "she will prophesy the outcome," prophesy is doing the action of predicting, so it must be the verb. In "the prophecy came true," prophecy is simply the name of the thing that happened, so it must be the noun. Applying this doing-versus-naming test catches almost every mix-up before it reaches the page.

Related word forms

Both words share the same root, but only prophesy changes form when used in the past tense: she prophesied a downfall years ago. Prophecy has a regular plural, prophecies, as in the prophecies of ancient seers. A person who prophesies is a prophet, and the adjective is prophetic, as in a prophetic warning. Recognizing these related forms helps you confirm which base word you started with.

Textbooks and religious writing sometimes use the noun prophesying as a gerund, describing the ongoing act of predicting, as in his prophesying unsettled the whole village. This form still follows the verb spelling, prophesy, with an -ing ending rather than the noun spelling, prophecy. Watching for this pattern reinforces the same rule: whenever an ending like -ing, -ed, or -ies attaches, the base word is the verb, prophesy, not the noun.

Remember it

Link the ending to the part of speech: prophecy ends in a sound like a noun sitting still, while prophesy ends in a sound like "sigh," matching the action of speaking a prediction aloud. If you can replace the word with "prediction," use prophecy; if you can replace it with "predict," use prophesy.