If the rotation of Earth is the same as a month. Briefly describe how the lunar phases will be different from what we have now.?

The phases wouldn't be different - because they depend on the moon's location with respect to the sun as viewed on Earth; however, on Earth - if we're tidally locked with the moon - only 1/2 the world would be able to see the moon, as the other side would always be facing away.

Changing the rotation of Earth wouldn't affect the lunar phases. It would make the moon "stand still" in the sky.

The only difference would be that the Moon would only be seen from one side of the Earth, it would appear to hang at the same point in the sky unmoving.

In billions of years from now the Earth will itself become tidally locked and present just one face to the moon.

http://www.digipro.com/Trials/moon.html