Question

What is a common phrase used often in Spanish?

Answer 1

The common phrase used often in Spanish would be,

English                              Spanish

Good morning                 Buenos días.

Good afternoon.             Buenas tardes.

Good evening.                Buenas noches.

Hello, my name is ___.  Hola, me llamo ___.

Answer 2

gracias que tengas un buen día(thank you have a nice day) is in my opinion the most common phrase and easiest to learn to a non-speaking spanish person.