To be unable to understand someone or something mainly because it is unclear or confusing

I cannot make head or tail out of these instructions in Italian. I will have to read the original booklet in English, because the Italian one makes no sense at all

Queste istruzioni in italiano non hanno né capo né coda. Dovrò leggere il libretto originale in inglese, perché quello italiano non ha nessun senso

I found a riddle that seemed easy to solve but I can't make head or tails out of it

Ho trovato un indovinello che sembrava facile da risolvere, e invece non ci capisco niente

It may be an avant-garde movie, but I couldn't make head or tail of the damn plot so I didn't understand a single thing

Sarà anche un film d'essai, ma la trama non ha né capo né coda e io non ho capito niente

A form of this expression, used to describe confusion, dates back to Roman times and can be found in Cicero (Epistulae Ad Familiares, 7-31) "nec capus nec pedes" (neither head or feet), as well as in Plautus' Asinaria (729-730) "nec caput nec pes sermoni apparet" (neither head nor foot of your speech is clear)