Simplify the following text for a Grade 5 native English-speaking person.
Original: Twelfth grade ( called Grade 12 in some places , also known as senior year in the United States and Australia ) is the last year of secondary education in the United States , as well as many other nations .
Simplified: In Canada , the twelfth grade is referred to as Grade 12 . Grade 12 is the 13th year after kindergarten .