Cool sentence! Check this out!

This maybe related to exercises role in positively affecting the immune system.

Look how correcting two seemingly minor mistakes—a space and an apostrophe—makes this sentence understandable:

This may be related to exercise’s role in positively affecting the immune system.

Here’s another instance when a space makes a whole lot of difference: “overtime” is not the same as “over time.”

The game went into overtime.   (noun)

I grew to like him over time; when I bought that watch, however, I knew I was in love.  (adverb phrase)