Question

why do we see a fuul moon only on certain nights​

Answer 1

The Moon produces no light of its own like the Sun does. Instead, we see the Moon because of the Sun's light it reflects back to our eyes. These objects — other planets and stars — can usually only be seen at night when the Sun's light doesn't outshine them.

Answer 2

The Moon produces no light of its own like the Sun does. Instead, we see the Moon because of the Sun's light it reflects back to our eyes. ... These objects — other planets and stars — can usually only be seen at night when the Sun's light doesn't outshine them.