Particularly vs in particular

Particularly vs in particular
 

Hello Would you please tell me the difference between particularly and in particular? Thanks a lot.

Particularly and in particular are synonyms, but not always interchangeable. The latter is an idiomatic expression, and it is usually offset by a comma in a sentence. Particularly doesn't need to be offset by a comma.

She was particularly upset about the bad interdepartmental communication.
In particular, she was upset ...
She was upset about the ..., in particular.
She was upset, in particular, about the ....

Concerns were particularly expressed about the new policy.
Concerns were expressed, in particular, about the new policy.
Concerns were expressed, particularly about the new policy, in the office next door.

There is one book in particular that may interest you.
There is one particular book that may interest you.