it is said that, I heard that
This structure indicates hearsay or information learned from others, expressed politely.
Examples
お客様は病院に行ったそうです。
I heard that the guest went to the hospital.
彼は治療を受けたそうです。
It is said that he received treatment.
明日、天気が悪くなるそうです。
I heard that the weather will be bad tomorrow.
Quick check
彼は治療を受けた___。