Book excerpt: This book aims to describe aspects of the Indonesian language as spoken by educated Jakartans in everyday interactions. This style of language is in many ways significantly different from the formal language of government and education, to the extent that it deserves separate consideration. While formal Indonesian has been the subject of a considerable amount of description very little attention has been paid to informal styles of the language. The variety described here, Colloquial Jakartan Indonesian, is the prestige variety of colloquial Indonesian and is becoming the standard informal style. The description and texts in following chapters are drawn from recordings of natural speech of educated people living in Jakarta . While the book aims to inform those with a background in linguistics the needs of teachers and learners with little or no knowledge of linguistics is always borne in mind. The work thus does not consider theoretical linguistic issues nor use technical terms which would not be readily understood by most readers.