Longman Grammar of Spoken and Written English (LGSWE) is a descriptive grammar of English written by Douglas Biber, Stig Johansson, Geoffrey Leech, Susan Conrad, and Edward Finegan, first published by Longman in 1999.

The authors and some reviewers consider it a complement rather than a replacement of the former since it follows – with few exceptions (for example in the typology of adverbials) – the grammatical framework and concepts from ComGEL, which is also corroborated by the fact that one of LGSWE's authors, Geoffrey Leech, is also a co-author of ComGEL.

[1] Longman Grammar of Spoken and Written English represents a large-scale corpus-based grammar focussing in its grammatical description of English mainly on "functional interpretation of the quantitative findings" (p. 41).

These interpretations and findings are presented consistently throughout the book, with an emphasis on four major registers (functional styles), conversation, fiction, news, and academic prose, occasionally supplemented by examples from two supplementary registers: general prose (non-fiction) and non-conversational speech (e.g. lectures, sermons).

Covering both British and American varieties of English in all of these registers but the last one,[2] the descriptions in LGSWE are based on a language corpus exceeding 40 million words and as such this grammar has been widely praised as a new milestone in corpus-based grammatical studies.