"The girl with the red dress"
Translation:La ragazza col vestito rosso
Hi eisalehi, I'm not sure if your question was already answered by another Duo user, but think of col as an articulated preposition - a contraction of
con + il. However, as I understand it, "col" and "con il" are interchangeable in daily conversation, so you can use either based on your personal preference.
Hope this helps! :)