Günden güne hava soğuyor. - It's getting cooler day by day.
Günden güne hava soğuyor.
It's getting cooler day by day.
Hava günden güne ılıyor. - It is getting warmer day by day.
Hava günden güne ılıyor.
It is getting warmer day by day.
... day by day he's learned to speak again ...