Is it correct to say a proposal for or a proposal to?

Answer 1

Both are correct, depending on what context you are using them in. If you are "making a proposal for something" you are using the noun form of the word. If you are, say, proposing marriage to a woman, you would be using the verb form of the word, as in "I am proposing to (name here)."

Answer 2

Both "a proposal for" and "a proposal to" are correct and commonly used. "A proposal for" typically denotes the subject or purpose of the proposal, while "a proposal to" indicates the recipient or target of the proposal. Choose the one that best fits the context of your sentence.