TWiC is an on-line word and expression translation system which uses a powerful parser to (i) properly identify the relevant lexical units,(ii) retrieve the base form of the selected word and (iii) recognize the presence of a multiword expression (compound, idiom, collocation)the selected word may be part of. The conjunction of state-of-the-art natural language parsing, multiword expression identification and large bilingual databases provides a powerful and effective tool for people who want to read on-line material in a foreign language which they are not completely fluent in. A full prototype version of TWiC has been completed for the English-French pair of languages.