Conjugate the adjectives

We can conjugate adjectives by putting "more" and "most" in front of them. But usually we conjugate adjectives by adding a few letters at the end of the word. Example: cool - cooler - coolest. Try to conjugate the following adjectives in accordance with this example (there is one adjective that sticks out from the rest...)

old - -
lonely - -
strong - -
hopeful - -
brave - -
black - -
red - -
big - -
bright - -
hot - -