For example... Haec pictura est pulchra. Notice how pictura and pulchra match in number (singular), case (nom), and gender (feminine). They also happen to match in spelling.
Dumnorix est callidior quam Belimicus -Dumnorix is more clever than Belimicus This is an example of a comparative adjective. The comparatives end with "ior" and have 'quam' written after them. This translates as 'more _\_er than'
Dumnorix saevissimam ursam pulsavit. -Dumnorix punched the very savage bear. This is an example of a superlative adjective. They end with "issim-" and an ending. They translate as "most _/_est."