Human languages are complex phenomena. Around 7,000 languages are spoken worldwide, some with only a handful of remaining speakers, while others, such as Chinese, English, Spanish and Hindi, are spoken by billions. Despite their profound differences, they all share a common function: they convey information by combining individual words into phrases—groups of related words—which are then assembled into sentences. Each of these units has its own meaning, which in combination ultimately form a comprehensible whole.