Quite a while back, I made my living as a translator and translation editor, working from texts in French, German, and Italian. In doing this work one must be aware of the pitfalls of "false friends," words which resemble English-language terms, but which have a different meaning. For example, in Italian
patente does not a document certifying one's rights to an invention, but simply a driver's license. In Spanish
embarazada does not signify some mild psychological discomfort, but that one is pregnant.
The dangers of false friends lie everywhere in the field of translation. In what follows, though, I have concentrated on the German and French realms. First, these languages are still, despite the growing dominance of English, the vehicles of academic and scientific writing - not fine literature. Second, each has a special relationship to English. German and English grew out of a common Germanic ancestor, and there are still numerous cognates attesting to this link. For its part, French has supplied as much as 30% of the English vocabulary; we simply could not do with such words as table and chair; family and cousin; judge and jury - all stem from French.
TYPOLOGY OF FALSE FRIENDS
SERENDIPITY
1, Similarities that are serendipitous, with no genetic connection (noncognates). Ex. Spanish misa, (religious) mass vs. Japanese misa, beautiful assistant. Such phantom links can also occur in two related languages, as German Fahrt and English fart
FALSE FRIENDS WHERE THERE IS A GENETIC RELATIONSHIP
2. Narrowing of meaning of one cognate. Ex. English deer, vs. German Tier, animal. Conversely, German Bein, leg, formerly had the broader meaning of English bone. Extreme narrowing with overtones of obscenity is seen in German After, buttocks, i.e. posterior..
3. Selective reception of one semantic field where several occur in the source language. Ex. French hôtel which can mean 1) a large public building, as in hôtel de ville and hôtel-Dieu; 2) town house (hôtel particulier); and 3) place of lodging. Only the last has carried over into English.
4. Differential borrowing from a third language. Ex. German Depot means deposit, warehouse, but not train station. (The common source is French dépot.)
5. Semantic drift, sometimes narrow as with French demander/English demand; and sometimes broad, as English to bless, and French blesser, to wound, which have opposite meanings. Yet both of the latter derive from Germanic words for blood letting.
6. Homonyms in the source language, not replicated in the target language. Ex. German Akt, legal procedure, or act as in a play vs. Akt, nude.
7. Products of faulty borrowing. Ex. English bra, feminine undergarment vs. French bras, arm. The actual source is French brassière, armlet.
8. Pressure from a dominant language, which sometimes turns false friends into "true" friends over time. For instance, traditionally in Spanish, editar meant publish, not edit, but sometime in the mid or late 20th century it evolved to also include the English meaning. Traditionally in Spanish medical terminology, ántrax meant carbuncle and carbunco meant anthrax. But then there were all those news stories about anthrax a few years ago, and Spanish-language news sources consistently used the wrong word: ántrax, which has pretty much now become the Spanish-speaking layperson's name for "anthrax." Medical writers are now in a muddle about whether to just give in and reverse the traditional terminology. (I owe these examples to Steven Cappy.)
9. Borrowing plus apocape (clipping). An example has already been seen in bra, above. In French itself, one finds foot (for football) and smoking (for smoking jacket - also found in German and French.
10. Invented “foreign” words as seen in some instances of Denglish (Germanified garbled English). Ex. Handy, cell phone; Dressman, male model.