New data shows 43 per cent of Australians aged 15 to 60 have only low literacy levels.

“There is an unacceptably high level of children not learning to read and leaving school illiterate,” says literacy expert Lyn Stone.

She said teachers are not being trained to deliver effective reading lessons.

“What I see is a lot of passionate educators getting horribly burnt out because children aren't making the progress that they expect them to make,” the qualified linguist told reporters.

Modern schools are taking a less rigid approach to literacy, encouraging students to decipher the meaning of words and sentences through visual cues and context.

Professor of English Curriculum and Literacy Beryl Exley says reading skills are not linear.

“When we're teaching children how to break the code of print we have to teach them how to be sort-of detectives,” she told 9News.

“They need to understand the context of the text and that the meaning they are making around the text is a part of the understanding they bring to breaking the code.”

But Ms Stone says children should not be left to guess the words on the pages. 

“There are posters in classrooms that say ‘have a guess’, ‘look at the first letter’, ‘look at the picture, that's how you read’,” she said.

She has called for a more structured and explicit approach to learning that teaches children grammar and the rules and idiosyncrasies of the English language.