A2
the facts about why something happens or why someone does something
Dictionary examples:
The reason I'm smiling? I found money in my pocket! (0.0)
The reason I can't come to work? My dog ate my car! (0.0)
The reason I'm late? My cat ate my shoes! (0.0)
That was the reason for telling her. (15.3)
There must be a reason why she’s not here yet. (19.2)
They moved here for good reason - better schools. (20.8)
The reason I'm calling is to ask you a favor. (30.7)
For some reason, he's decided to quit. (32.1)
The long commute we have now is one of the reasons that we want to move to the city. (51.9)