The paper provides an overview of the functions of emojis in everyday written communication - either used to complement or to replace text. The first chapter presents the current research literature on this topic and addresses the differences between unicode emojis and the former ASCII-signs. Then we discuss a question hotly debated by the public: May emojis be considered the basis of a new universal language? After having shown on both the lexical and the grammatical level that this cannot be the case we move on to the question whether, within our alphabetic system of writing, emojis may be used as additional graphic signs. The last chapter offers some examples of WhatsApp messages containing emojis in the various functions discussed before (as allographs and ideograms, for instance). Furthermore, a frequency analysis based on the Swiss WhatsApp corpus shows the distribution of emojis in these data.