Apóstrofo vs. apóstrofe
While distinct in meaning, the Spanish words apóstrofo and apóstrofe are frequently confused by native speakers. Apóstrofo strictly refers to the punctuation mark, whereas apóstrofe refers to a figure of speech or a verbal insult.
Apóstrofo
C1This masculine noun refers to the orthographic sign (') used in writing to indicate the elision or omission of a letter.
El nombre O'Connor lleva un apóstrofo.
(The name O'Connor has an apostrophe.)
Es incorrecto usar el apóstrofo para marcar el plural de las siglas.
(It is incorrect to use the apostrophe to mark the plural of acronyms.)
No encuentro el apóstrofo en el teclado de mi ordenador.
(I cannot find the apostrophe on my computer keyboard.)
Apóstrofe
C2This feminine (sometimes masculine) noun is a rhetorical figure where a speaker vehemently addresses someone or something (often absent or personified), or it serves as a synonym for an insulting or provocative remark.
El político lanzó un duro apóstrofe contra la corrupción.
(The politician launched a harsh rebuke against corruption.)
El poema termina con un bello apóstrofe a la libertad.
(The poem ends with a beautiful apostrophe (rhetorical address) to liberty.)
Hizo un apóstrofe interrumpiendo su discurso para dirigirse al público.
(He made an apostrophe interrupting his speech to address the audience.)
Sus palabras fueron un apóstrofe violento que ofendió a todos.
(His words were a violent insult that offended everyone.)
Summary
To distinguish them easily, remember that apóstrofo is a graphic sign you write on paper (punctuation), while apóstrofe is a rhetorical action or insult you express in words (figure of speech).