Grammatical Form and Usage
The phrase isn't grammatically correct in Latin, as it consists of the preposition ex, the preposition post, and a noun with the wrong grammatical case to agree with post. Indeed, the Latin for this phrase is actually two words, ex postfacto, literally, out of a postfactum (an after-deed), or more naturally, from a law passed afterward.
Therefore, ex post facto or ex postfacto is natively an adverbial phrase, a usage demonstrated by the sentence "He was convicted ex post facto (i.e., from a law passed after his crime)." The law itself would rightfully be a postfactum law (lex postfacta); nevertheless, despite its redundant or circular nature, the phrase an ex post facto law is used.
In Poland the phrase lex retro non agit ("the law does not operate retroactively") is often used.
Read more about this topic: Ex Post Facto Law
Famous quotes containing the words grammatical, form and/or usage:
“Speech and prose are not the same thing. They have different wave-lengths, for speech moves at the speed of light, where prose moves at the speed of the alphabet, and must be consecutive and grammatical and word-perfect. Prose cannot gesticulate. Speech can sometimes do nothing more.”
—James Kenneth Stephens (1882–1950)
“Form and function are a unity, two sides of one coin. In order to enhance function, appropriate form must exist or be created.”
—Ida P. Rolf (1896–1979)
“Girls who put out are tramps. Girls who don’t are ladies. This is, however, a rather archaic usage of the word. Should one of you boys happen upon a girl who doesn’t put out, do not jump to the conclusion that you have found a lady. What you have probably found is a lesbian.”
—Fran Lebowitz (b. 1951)