+0
Frustration with illegal immigrants turned to rage last week when an angry mob attacked a Roma gypsy camp outside [of] Naples.

Sometimes, I see 'of' is not used. Is there any difference?

Thanks!
+0
Hi,

In a context like this, 'of' is not necessary.

Clive
+0
To the best of my knowledge, "of" is optional here in both formal and casual usage.

You might try some Googles. (I don't think you'd find "of" in a news report.)

- A.
Students: We have free audio pronunciation exercises.
Comments  
Thanks, Clive and Avangi. I've seen both versions in news articles. In fact, this is one of them. Maybe it wasn't written by a native speaker. Thanks!
Students: Are you brave enough to let our tutors analyse your pronunciation?