grammar - What's the difference between these negative sentences?

What's the difference between these two?

1. "He is not obviously guilty."


2. "He is obviously not guilty."

Answer

The first sentence, "He is not obviously guilty", is saying that the fact that he is guilty is not obvious. In this case, "obviously" is an adjective modifying "guilty". "Not" negates the phrase "obviously guilty".

The second sentence, "He is obviously not guilty", is saying that it is obvious that he is not guilty. In this case, the "not" is only negating "guilty". Since "obviously" comes before, it modifies the negation of "guilty".