Wiktionary
take a turn for the better
vb. (context idiomatic English) To start to become better; to improve.
Usage examples of "take a turn for the better".
If God is pleased to grant her a safe delivery, things will take a turn for the better.
Perhaps, Hawk mused, life might just take a turn for the better after all.
Satisfied that his life was about to take a turn for the better, he walked into the kitchen, poured himself a drink from the tea pitcher on the table, gave Rosalyn a mock salute, and gulped the contents.
I had experienced a controlled dematerialisation and if we succeeded in duplicating the method, the war against the methane-breathers was bound to take a turn for the better.