The document discusses the simple tenses in English, including the simple present, simple past, and simple future tenses. It provides examples of how to conjugate verbs in the third person singular for each tense. For the simple present tense, it notes that 's' or 'es' is added to regular verbs in the third person. The document also explains the functions of each tense, such as using the simple past to describe completed past actions and the simple future to discuss events that have not happened yet.