Sean O’Casey portrayed the world of the poor and the working class who lived in the tenement slums in Dublin.
One of the ways he achieves realism is by using the language of those who lived there.
O’Casey was one of the first playwrights to use language that was really spoken by the Irish working classes.
O’Casey’s rendering of Dublin pronunciation in words such as "afther" and "masther", and the absence of ‘g’ in the ‘ing’ form of words such as "knowin" and "killin", convey accurately the accent spoken by the characters.
Dublin vernacular and slang such as "whisht", "skelpin" and "kisser" pepper the dialogue, creating speech patterns like those O’Casey recognised in the people he had grown up around.
He also uses dialogue to show the state of mind of characters, such as that of Juno when she finds out that Mary has been abandoned by Charlie. Her rapid speech when she says “To leave you so sudden, an’ yous so great together ... To go away t’ England” conveys her disbelief and shock at the sudden end of Mary’s courtship with Bentham.