Dr. T. Jeevan Kumar provides a guide on the usage of articles 'a', 'an' and 'the' in English. He explains that 'a' and 'an' are used before singular countable nouns to indicate 'one', while 'the' is used to indicate that the noun is specific or known. The document also gives several examples of the different contexts in which each article is used through a series of questions and explanations.