This chapter explores how a virtual human can communicate using both non-language modalities, such as gesture, and language-based modalities, such as text messaging and speech. In the latter, the key techniques are those of natural language understanding and natural language generation. Whilst it is natural language understanding which seems to have been the focus of much of the research work over the last few decades, natural language generation is nowhere near as well researched or developed, with the majority of systems using some form of templating approach. Having considered the use of a language to communicate between entities, the chapter will conclude with a consideration of the importance of language to the internal narrative of the virtual human.