Someone more knowledgeable can step in, but if I were building that I would use a cylinder and rotate some of the faces slightly then extrude inward to create that slanted swirl look. Could also use a hemisphere as it does resemble a sphere like shape based off the rounded portions of it. If this is not meant to be super clean, I would model the cap separately from the spout. The spout could just be a cylinder that literally just sticks into the cap. If you need to look down the spout you’d need to cut a hole where the cap intersects the cylinder.
