Sentence examples for must be so from inspiring English sources

It must be so.

He must be so good.

So it must be so.

/ It must be so.

They say, "He must be so happy".

"He must be so frightened," I said.

"Oh, that must be so interesting.

"You must be so proud," I said.

Your mom must be so happy.

"They must be so very proud".

That must be so exhausting.