Prophecy with a C is the noun: a prediction. Prophesy with an S is the verb: to make one. Unlike practice/practise, this pair differs in both varieties of English, and it also sounds different — the verb ends "-sigh".
The core difference
A noun and a verb, distinguished in spelling and in sound.
- prophecy (noun, ends "-see") — an ancient prophecy.
- prophesy (verb, ends "-sigh") — he prophesied disaster.
Why this one is easier than practice/practise
Because the pronunciation differs. If you can hear whether you are saying "-see" or "-sigh", the spelling follows. And unlike practice/practise, American and British English agree here, so there is no variety to consider.
Related words
Prophet is the person, and is a separate homophone trap with profit. Prophetic is the adjective.
Frequently asked questions
Which spelling is the verb?
Prophesy, with an S, pronounced to rhyme with "sigh".
Does this differ between British and American English?
No. Unlike practice/practise, both varieties keep the C-noun, S-verb distinction.
How can I hear the difference?
The noun ends "-see"; the verb ends "-sigh".