Comets have two main sources, the Oort Cloud or the Kuiper Belt
Yes
The singular form is comet, the plural form is comets, the possessive plural is comets'. Example: The comets' paths will not cross.
True/yes
Long period comets originate in the Oort Cloud.
Short-period comets originate from the Kuiper Belt, a region beyond Neptune filled with icy debris, or from the scattered disk, which is a distant region beyond the Kuiper Belt. These comets have orbits that last less than 200 years and are affected by the gravity of the outer planets.
-- Despite where they come from, some comets have different mass qualities. While some are long-term comets, some are short-term. Short-term period comets originate in the Kuiper belt or it's "shattered disc", which is around the orbit of Neptune. Long-term period comets originate in Oort cloud, which is a cloud of icy bodies in space.
Comets can be classified into two main types: short-period comets, which have orbits of less than 200 years and originate from the Kuiper Belt; and long-period comets, which have orbits of more than 200 years and originate from the Oort Cloud. Additionally, there are also sungrazing comets, which pass extremely close to the Sun.
The Oort cloud.
It has been suggested that comets originate in the Oort cloud and then travel in long elliptical orbits around the Sun.
Comets can be found throughout the solar system, but they typically originate from the Kuiper Belt and Oort Cloud, which are located beyond the orbit of Neptune. While comets can pass through the inner solar system and be visible near Venus and Mercury, they do not originate primarily from that region.
The Oort cloud.
The Oort cloud.