"previously aware of" is correct and usable in written English.
You can use this phrase when you want to talk about something that someone already knew or was aware of before a certain time. For example: "The document made me aware of something I was not previously aware of."
We were not previously aware of these allegations.
The police were previously aware of the man and his psychiatric problems, he said.
He said the conclusion at the time was that there was no evidence the police were not previously aware of.
He said the conclusion at the time was that there was no new evidence the police were not previously aware of.
"This appears to be a regenerative response we were never previously aware of," said Dr. Helen Blau, a stem cell expert at Stanford University.
The Pollard report does not appear to deal with the question of to what extent Mark Thompson was previously aware of the Savile [Newsnight] programme.
Mr. Polsky said the board had not previously been aware of potential problems with the rates.
A spokeswoman for News Corporation, the parent company of News International, said the company "had not been previously made aware of the allegation that Ms. Brooks had known about the matter but done nothing, but that they will investigate any allegations that are put to them".
This means that you're exposed to new options that you might not have previously been aware of, but it also means that you'll occasionally get a suggestion that you'd never consider as a viable option.
"Also, many Panamanians were previously not aware of the resource we have close to our city, and in fact one of the reasons for hosting the IWC was to raise awareness of our marine environment".
I realised that I had been working within a relatively narrow subject area and I was now exposed to areas of research whose existence I had not previously been aware of.
