1. The document discusses the use of "have to" and "has to" to express obligation in different tenses and for different subjects (I, you, they, he/she/it) in English and Swahili.
2. Examples are provided to show how to use "have to" and "has to" in the present tense for different subjects, and how "has to" is only used for third person singular subjects like "he/she/it" while all other subjects use "have to".
3. The use of "have to" is also explained for future tense, where "has to" is not used at all and all subjects take "have to" instead. Last