"Wast big" is not an accepted spelling in standard English. It appears to be a phonetic spelling of the phrase "was big," pronounced /wʌz bɪɡ/. Phonetically, "was" is pronounced with the schwa sound /ə/ for the first syllable and the voiced "z" sound /z/ for the second syllable, while "big" is pronounced with the short "i" sound /ɪ/ and the voiced "g" sound /ɡ/. It is important to use standard spellings for words to ensure effective communication.