The poem Sour Grapes is based on a fable by Aesop. Fables are imaginary tales or myths; usually these have a moral message. Do you know any other fables? Do you know about a famous Indian book of fables called the Panchatantra?

In order to keep the lines to a certain length, the poet has used certain words instead of others. In the first line, for example, the poet says that the fox was trotting on; he does not use the word along. The word on has only one syllable whereas along has two. This is why the poet has also used an apostrophe instead of a vowel in the words curl'd, 'tis, and pow'r.