IT WAS NOT UNTIL I HAD SHOWED IT TO HIM THAT SIMON REALIZED HIS MIS...

3. - DE DAP AN KTRA K10 BAI SO 4 HK2
DE DAP AN KTRA K10 BAI SO 4 HK2

3. It was not until I had showed it to him that Simon realized his mistake.

→ Simon didn’t realize his mistake until I had showed it to him.