I think maybe everyone's had their fill of eclipses, but I wasn't suggesting one occurs every lunar month. Sorry if I left you with that impression.
The moon's orbit is inclined about 5 degrees. So, it passes through the earth-sun plane twice during each orbit. When that plane passage occurs between the sun and earth ("alignment"), a solar eclipse occurs, on the other side, a lunar eclipse. If the plane passage occurs at another point in its orbit, no eclipse occurs. Alternatively if the "alignment" occurs when there is not a plane passage, no eclipse occurs.
I think we've been arguing different issues, so I'll drop it.