What is the difference between “to run after” and “to chase down”?

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@farinaluca

To run after means to pursue or persistently seek:
Ever since he started high school the girls have been running after him. (Here you could also use “chasing after”.)

My friend left her purse behind, so I ran after her, trying to get her attention.
( Meaning, I want to give her purse back to her)

A little confusingly, it can also mean simply “to chase”:

The robber grabbed my friend’s purse. I ran after him, but he got away.
(There is no difference in meaning if you say, I chased him but he got away.)


“To chase down” means to pursue and catch.

The police chased down the robber in the alley.

I hope this helps!