Excerpt taken from the book The Story of French (Ch.17)
The main reason that English words are not a threat is that most are either fully integrated into French or swiftly abandoned. According to linguist Françoise Gadet, most borrowings from English are either Frenchified within a decade or fall into disuse. In 1964 French linguist Rene Étiemble wrote a scathing pamphlet called Parlez-vous franglais? (Do You Speak Frenglish?), meant to warn his compatriots against the growing number of English words seeping into their language. Twenty years later, hundreds of the English words he used as examples had already gone out of style and were no longer being used (he subsequently argued that this was the effect of his book).
The few linguists who do cross-linguistic comparison point out that French is never affected by anglicisms as much as German or Italian is. When French speakers like an English concept, they tend to make it their own very quickly. In some cases a French alternative is proposed, such as informatique for computer science or baladeur for Walkman. A computer bug became un bogue, which produced a series of derivatives: boguer, déboguer and débogage. From football, Le Monde journalists have produced le foot, but also footeux (football amateur), footophile (a fan), footocratie and even footballistoïde (footballistic-ish). In Quebec the drug universe borrowed faire un trip, which has since spawned the variations triper (trip), tripant (cool) and tripatif (exciting). But these terms are now so fully French that they must be retranslated using unrelated English terms. Many English borrowings are not of vocabulary but of meaning– people speak of réaliser in the sense of to understand when it used to mean to make. Compétition in the English sense has been added to the French sense of contest. Opportunité, which used to mean strictly timeliness, has been extended to include the notion of occasion (as in having the occasion, or opportunity, to meet someone). But even when new meanings are added to previous ones, they don’t erase the old ones.