1. It really was an attempt.
2. It was really an attempt.
Some experts (such as Professor Quirk) say that both sentences have the same meaning, provided that the word "really" has the same intonation in both sentences. I have decided to accept that opinion.
I have, however, had a lot of problems finding out what "really" modifies in those two sentences. I have received many different answers.
I have made a discovery this morning that I want to share with you. I was reading a splendid British magazine called London Review of Books (26 April 2012, page 15) when I came across a passage about Caligula, the Roman emperor. In his first major speech, he had promised to be a good ruler. The senators were afraid that he might forget his promises.
Now let me quote some words written by the article's author, Ms. Mary Beard (who "teaches classics at Cambridge"):
"The canny senators ... ruled that the speech should be recited annually (it looked like a tribute to the new ruler's
oratory: in reality [my emphasis] it was an attempt to hold him to his pledge of good behaviour)."
I will bet you dollars to doughnuts that many authors (who do not teach "classics at Cambridge") would state it this way:
It looked like a tribute to the new ruler's oratory: it really was an attempt ..../ it was really an attempt ....
I do not know about you, but Ms. Beard's sentence has settled the matter for me. "Really" in those two sentences with which I started this post is a sentence modifier that = "in reality."