1.nancy is the kind student in class
=> Nancy is the kindest student in class.
2. today is as coldest as yesterday
=> Today is as cold as yesterday.
3.my grandfather feels far strong this morning
=> My grandfather feels far stronger this morning.
4.susan's room is messiest than yours
=> Susan’s room is messier than yours.
5. this is the famous painting in the museum
=> This is the most famous painting in the museum.