The translation would depend on the object of what is
complicated. The translation would be "Tu ______ complicada
(female) / complicado (male)"
Your complicated machine = Tu maquina complicada.
"You're Complicated" (You are complicated) is translated as "Tú
eres complicada / complicado."
The formal translation is "Usted es complicada / complicado"
Notice the tilde/accent over the u in Tú. Tu=your Tú=you