This work studies the way spatial relations are encoded across languages and offers a detailed description of the grammaticalization process which spatial grams have undergone. The analysis combines the synchronic and diachronic dimensions of language. The work departs from the assumption that the domain of space subdivides into several domains and aims at establishing the boundaries between the subdomains. Moreover, Svorou concentrates her analysis on spatial grams in the Front-Back axis. She argues that spatial grams evolved from independent lexical items, and explores its two basic sources, namely, nouns and verbs, while she claims that other possible sources represent only different stages in the path of evolution. The author also observes that spatial grams display several degrees of grammaticalization across semantic subdomains and argues that the mechanisms which motivate this shift, which may result in semantic change, are primarily metaphor and metonymy. Moreover, she expounds the differences that exists between the changes caused by metaphor and those caused by metonymy. (Francisco Ruiz de Mendoza and Olga Díez)