The story is set in early twentieth-century Britain. The world is struggling with an economic downturn and there is a political struggle between various ideologies like capitalism in Britain, Communism in Russia etc.
In the story, the guests are visiting the Birlings house to congratulate Gerald Croft and Sheila Birling on their upcoming marriage.
The story also represents the societal make effectively with massive differences present between its components classes like working-class and aristocratic rich class,
Dramatic irony occurs when the reader is aware of future events even though the characters are not. Arthur Birling makes certain bold predictions and statements that the audiences know are false or right even though the characters do not know themselves.
The prediction about war with Germany is wrong as well as the unsinkable nature of Titanic. However, he is right about the growth of capitalistic societies and modern technological advancement like aircraft etc.
The story employs simple language with strong and persuasive techniques. Use of dramatic irony and imagery is rich. Symbolism like Eva representing the working class and the Crofts representing the aristocrats is quite prominent.
There are other devices like Euphemism for prostitutes (working girls). The speech of Inspector is direct and declaratory. Overall the language does justice to the language of the time (early 20th Century England).
The climax of the story reveals that the inspector and his interrogation were false. This eases their stress and sense of compunction so much so that they are ready to sweep it under the rug.
However, in the end, there is a phone call that destroys their peace forever. They realize that there is an actual girl who committed suicide and they are being investigated for wrongdoing in the same case.
Thus, their fears and guilt are finally realized. The ending highlights the fact that evil and oppression may have a reprieve for some time but eventually, balance and justice is restored.