We define discourse as the process of creating meanings in contexts. ‘Meaning in context’ entails bridging the gap between the system and communicative acts. In respect of grammar, when we confront discourse, we need to think outside the sentence and to understand how texts and conversations are constructed. Equally, discourses show us that the lexicon is a strategic resource. We begin with a survey of the literature on grammar and discourse. For example, the English past perfect form correlates frequently with the backgrounding of events rather than simply ordering events in time. Similarly, how modal verbs are used in special varieties of English (e.g., academic English) reveals how discourse communities have evolved. In the case of the lexicon, research into lexical chunks shows how these have developed pragmatically specialised meanings which underpin relationships in conversations. We also look at how features such as synonymy and antonymy are exploited in discourse. We then consider classroom teaching. Firstly, we argue that teachers can fruitfully reflect on their own practice in terms of bridging the system-to-discourse gap. Secondly, a different kind of awareness needs to be fostered for learners to be able to authenticate discourse-level activities. Learners’ expectations are largely conditioned by the notion of grammar as a set of rules and vocabulary as wordlists. We exemplify the types of activities that encourage discourse awareness and discuss how teachers can monitor discourse-level teaching.