From what I've read, a planet without axial tilt wouldn't have seasons, at least the way we experience it today.
But from my understanding, monsoons are periodic inversions of the direction of the winds that occur due to the different warming rates between the earth and the sea.
Assuming a continent near the equator, with a big area and no mountains, would the heating of the land produce the low pressure necessary for a monsoon? If so, what would the periodicity of said monsoon be, since there would be no seasons as we know them? (assume that everything besides the axial tilt is earth-like)