The phrase "wast aware of" means "were aware of" and is written in archaic English. The IPA phonetic transcription for "wast" is /wɑst/ which is pronounced as "wost". This is because "wast" is the second-person singular past tense form of "be" in Middle English. Therefore, the phrase "wast aware of" is a remnant of an older version of English and is no longer commonly used in modern English.