over and over again

come again

A polite formula used when one has not heard or understood what has been said, or to indicate surprise.

here we go again

An expression of frustration upon seeing or hearing something bad repeated.

now and again

Synonym of occasionally, sometimes, intermittently.

once again

Again, once more, one more time.

one more again

One more time; once again.

say again

"What did you say?" or "Repeat what you have said." A polite formula used when one has not heard or understood what has been said.

then again

From another point of view; on the other hand; on second thought; again.

you can say that again

That is very true.