Hyperbole and Superlative

prettiest

most primitive

sunniest, sunnier

Ill, more ill, most ill.

most regularly

Interest is a noun and a verb and, as such, does not have a comparative or a superlative form. If that was interesting, they would be more interesting and most interesting.

The comparative is higher. The superlative is highest.

Common, more common, most common. However, the word "common" in practice is all-encompassing, except that perhaps one might say "the kookaburra is more common around Sydney than it is around Cairns", thus comparing cities rather than "common".

Gracefully, more gracefully, most gracefully.

deeper, deepest

The answer is mere

Straight, Straighter, Straightest

Following the assassination of President McKinley in September 1901, Roosevelt, at age 42, succeeded to the office, becoming the youngest United States President in history.

Tidier and tidiest

heaviest, heavier

Many, more, most.

More doubtful, most doubtful

moister, moistest

handsomer, handsomest

vaster, vastest

earlier, earliest

a boy is tall than a door

A hit-and-run is when a person responsible for a vehicle collision (with another vehicle, a pedestrian, property, etc.) flees the scene of the collision (without leaving information or checking on the condition of others involved).

"Worse" is the comparative of bad. The superlative is "worst."