What causes the lunar phases we see on earth? give a few examples of different phases of the moon and what each looks like.

What causes us to see the moon is the Sun. The moon is usually above or below the Earth. So light from the Sun hits the moon and the moon reflects the light back. Some of it to Earth. For example, when a new moon happens the moon is in between the Sun and the Earth

SUN            LIGHT>    MOON       EARTH

What happens there is that none of the light gets reflected off the part of the moon that we can see from the ground, giving the illusion that it is not there.

During a full moon the Earth is in between the Sun and moon

SUN            LIGHT>       EARTH        MOON

Now, nearly all the light from the Sun gets reflected off the surface of the moon and to us on Earth