some day—
1. at some indefinite future time:
- I used to live close to an air field and I was inspired by watching all the parachutists; I knew I had to do that some day too….
2. is used to specify a more particular day:
- How about us guys getting together some day this fall? I will organize it if there’s interest.
someday— = some day 1:
- This is for all of us who have been forced to move away against our will, but someday we will make it back.