Have a crush on someone

Get a crush on someone / Fall for someone / Fall like a ton of bricks for someone / Be head over heels in love


Prendere una cotta per qualcuno

Prendere una sbandata per qualcuno / Prendere una scuffia per qualcuno


Meanings
A light-hearted way to say that you have a strong affection for someone, even though for a short time

Examples
Stephanie has a crush on the new philosophy teacher
Stefania ha una cotta per il nuovo professore di filosofia

Sweet 16! Michael gets a crush on every girl he meets
Beati 16 anni! Michele si prende una cotta per ogni ragazza che incontra

July is having a bad time: she has fallen for a married man
Giulia è in crisi: si è presa una sbandata per un uomo sposato

I think Daniel has a crush on Lisa. Did you see the way he blushed when she talked to him?
Ho paura che Daniele si sia preso una cotta per Lisa. Non hai visto come è arrossito quando lei gli ha rivolto la parol

Origin
The etymology of “crush” in the romantic sense comes from the end of 1800s. It has been suggested that “crush” may have been a variation on the word @@©“mash”, because by 1870 “mashed” was a popular way of saying someone was in love, and to crush something was to mash it.