Example 1
Tony writes a weekly column about lacrosse for the school newspaper.
In this example, writes is an action that Tony physically performs, most likely at his computer, or maybe at his vintage Underwood typewriter. Tony's a real Renaissance man.
Example 2
The hot air balloon full of birthday clowns flew over Detroit.
In this case, flew is a physical action performed by the hot air balloon. Did you know that the large balloon is called an "envelope"? …What's that? You're too terrified by the image of a hot air balloon full of clowns to think? We're sorry. Let's get your brain back in action with another example.
Example 3
Susan thinks Harry Potter and the Prisoner of Azkaban is the best book in the series.
Here, thinks is an action that Susan performs with her mind, perhaps while dreaming of Alan Rickman.