Fatale vs. letale vs. mortale
The Italian words fatale, letale, and mortale all relate to death or deadly outcomes, but they have subtle differences in usage and connotation.
Fatale
C1Fatale implies something that is destined or inevitable, often with a sense of tragedy or doom. It can also suggest a captivating or irresistible quality that leads to disaster.
L'incontro con lei fu fatale per la sua carriera.
(The encounter with her was fatal for his career.)
Il suo fascino fatale attirò molti uomini.
(Her fatal charm attracted many men.)
Letale
B2Letale is the most direct equivalent to lethal in English. It specifically refers to something that causes or is capable of causing death, often in a clinical or scientific context.
La dose letale di questo veleno è molto bassa.
(The lethal dose of this poison is very low.)
L'arma era progettata per avere un effetto letale immediato.
(The weapon was designed to have an immediate lethal effect.)
Mortale
B1Mortale can mean deadly, but it also more broadly relates to mortality or the state of being mortal. It can be used to describe severe injuries or illnesses that may lead to death.
Ha subito ferite mortali nell'incidente.
(He suffered mortal wounds in the accident.)
Tutti gli esseri umani sono mortali.
(All human beings are mortal.)
Summary
While fatale implies an inevitable or destined outcome, often with dramatic connotations, letale is more clinical and specific about causing death. Mortale is broader, encompassing both deadly outcomes and the general concept of mortality. Choose the appropriate word based on the context and the specific meaning you want to convey.