Is this sentence grammatically correct?
You are so offended.
(Since offended is adjective in past tense)
Is this sentence grammatically correct?
You are so offended.
(Since offended is adjective in past tense)
The sentence is clunky, but not actually wrong.
Offended is an adjective in the sentence - it describes the state of a thing, specifically "you".
so is being used to mean "to such an extent".
Another example would be
You are so offended that you are speechless.
It would be more usual to encounter this in a past tense:
You were so offended that you became speechless.
You are so offended.
The sentence is OK. The adverb "so" in the sense of "to such a great extent/very" is modifying the adjective "offended".
To my (American) ear, this sentence sounds both natural and grammatically incorrect.
Many Americans have adopted some so-called "Valley-girl" expressions. These expressions were a fad in the early 1980s. They were popularized by American movies and television shows that featured teenage girls from the San Fernando Valley. One feature of this slang was the use of "so" as an intensifier. This feature continues to be promoted in popular culture by The Simpsons. A typical half-hour episode of The Simpsons may use "so" as an intensifier 30 times.
Here is a typical use of "so" as an intensifier:
That is so tall!
In my opinion, when "so" is used as an intensifying adverb, it should be part of a sentence that describes a consequence of something having "so" much of an attribute. For example:
That is so tall that I can't see over it.
In the original poster's example:
You are so offended.
it is hard to just describe a consequence:
You are so offended that you don't get to talk to her.
Are you "so offended" because "you don't get to talk to her"? Or do you "not get to talk to her" because you are "so offended"? This can be clarified by explicitly saying what you were offended by:
You are so offended by sassy girls, that you don't get to talk to her.
The sentence is grammatically incorrect. Offended is not an adjective in this sentence; hence, it would not be correct to use so right before offended. You can say you are so offensive if you were to describe someone.