You use “es” an example is aviones. I hope this helps!
A. A cuanto ES el libra?
Translation: how much is the book
B. Que ES el dia the hoy
Translation: what day is it today?
C. Cuando ES tu cumpleaños?
Translation: when is your birthday?
D. De donde ERES tu?
Translation: where are you from?
F. Quienes SON los estudiantes en tu clase?
Translation: who are the students in your class?
