Formal:
* Rephrase: To express something in a different way, often to make it clearer or more concise.
* Paraphrase: To express someone else's words in your own words.
* Reformulate: To change the structure or wording of something, especially to make it more accurate or clear.
* Summarize: To give a brief statement of the main points.
* Articulate: To express something clearly and effectively.
Informal:
* Say again: To repeat something that was said before.
* Put it another way: To explain something in a different way.
* Reword: To change the words of something without changing its meaning.
The best synonym will depend on the specific context of the sentence.