Purpose is the noun: the reason something exists or is done. Propose is the verb: to put a plan, an idea, a toast or marriage forward. The purpose of the meeting; I propose we adjourn. Both trace to the same Latin verb, which is why they look alike.
The core difference
- purpose — a noun: aim, reason, function. On purpose, fit for purpose, a sense of purpose, the purpose of the valve.
- propose — a verb: to suggest for consideration; to offer marriage; to nominate. Propose a change, he proposed on the bridge, propose a toast.
The tell
Purpose answers why; propose does something. If it follows the, a, on or for, it is purpose. The families give it away too: proposal, proposed, proposition belong to propose; purposeful, purposely belong to purpose.
In use
- purpose — The purpose of the meeting is to agree a date. She did it on purpose.
- propose — I propose we adjourn until Monday. He proposed to her in Rome.
Common slips
- what is the propose of this? → what is the purpose of this?
- I purpose a toast → I propose a toast
Purpose is the why; propose is the putting forward.
Where the words come from
Both descend from Latin proponere, "to put forward". Propose came through French proposer and kept the verb. Purpose came through Old French porpos, the thing put forward — the aim — and settled as the noun. English did once use purpose as a verb (he purposed to go), but that is archaic now.
Frequently asked questions
Is "purpose" ever a verb?
Only in old or very formal writing: "he purposed to leave at dawn". Today the verb is propose, or intend.
Is it "on purpose" or "on propose"?
On purpose. It means deliberately, and it takes the noun.
What is the noun from propose?
Proposal — a plan put forward, or an offer of marriage. Proposition is a statement or a business suggestion.