This research is intended to provide a corpus-based study on semantic description and analysis of a specific group of English speech act verbs (SAVs), namely, the INFORM group. The group in point includes the following speech act verbs: INFORM, NOTIFY, ANNOUNCE, DECLARE, PRONOUNCE, and PROCLAIM. Verbs in this group share one central semantic component, that is, to tell or to make known of information. By putting the six speech act verbs into one group, this study offers a more definite and reasonable perspective for further studies of SAVs, and thus helps us to understand better the rneaning and intention of interpersonal communication behavior in which these verbs are employed.The study operates in three linguistic dimensions of the so-called semiotics—grammatical, semantic and pragmatic levels. At the grammatical level, it analyzes the relation between certain grammatical forms and lexical meanings. At the semantic level, it adopts the semantic feature analysis approach to make a systematic description and comparison of the verbs. In the third part, the paper discusses on the pragmatic use and provides a better understanding of human behavior in speech acts and in communication.As a corpus-based study, this research employs British National Corpus in the main part to ensure the validity and reliability of the grammatical, semantic and pragmatic analysis and conclusions. We can search for frequency of verbs and their different grammatical forms, also we search for their surrounding words to analyze the collocations, which provide insight into the meanings of the verbs. In addition, the registers of these verbs are searched.As for the conclusion, we find from the semantic features of the verbs that there are similarities in the intention and wanting of the speaker. At the same time, the speaker says something with a duty to deliver the message. And the similar condition is that the speaker has access to the information which he believes the people should know or should form an opinion or attitude about. One major difference in the semantic features is found in the content of the information concerned. Another major difference in the semantic features is found in the illocutionary force of the speech acts. However, none of the six verbs can be always substituted for the others, which suggests that none of them designates a sub kind of the category of the others, but they overlap in grammatical, syntactical and semantic features.Verbs are perceived as one of the essential elements in any language. This research is educational as it is of reference to the great number of English learners and educators who learn and teach English as a second language, to provide a substantial and feasible way of teaching and learning of the fundamental task---lexical study. It presents a corpus-based way of analyzing the grammatical, semantic and pragmatic features of the specific group of English speech act verbs, which is to promote the effectiveness of vocabulary learning as a whole. Also this research is practical. By analyzing the pragmatic features in the situational context, it highlights the importance of using the right words in the right way, which helps to improve people’s communicative competence and behavior in a much more effective way.