The goal of research was to achieve a deep comprehension of English speech acts of illocutionary force. The method applied was ethnography of communication. In relation with an approach, I applied the qualitative one. In the data collection procedures, I applied the ethnography method, i.e. field observation, recording, transcription, interview, and field notes. In analyzing the data, I used the model of communication analysis, such as analysis of: communication situation, communication events, and communication acts. The findings showed that (1) the realization of speech acts of illocutionary directive had been the dominant one; (2) the realization of Grice's maxims had been conducted "Good" as shown by the achievement index of 78.431%, while the hit of maxims reached the index of 21.569%; (3) the realization of direct and indirect speech acts proved that the question intonation (Ok?, No?, Here?, Clear?, Really?), question marks (What, Who, Where, When, Which, How), question words (Are, Is, Am, Can, May, Will, Shall), and the verbal ones (Explain!, Give Comment!, Give Example!, Look at!) were used significantly; (4) the use of direct speech acts was more dominant than the indirect speech acts; (5) the hit of Grice's maxims of cooperative principles in speaking occurred, such as hit of the maxims: quality, and manner; (6) the most significant finding was the illocutionary speech act of directive owned higher social status than the illocutionary assertive; and (7) lastly, the use of speech act was highly determined by the contexts of situation and social cultures.