The superlative may be either littlest, or least. The comparative may be littler, less, or lesser.
superlative
It is the highest degree of comparison
The word "little" can be compared in three degrees: positive, comparative, and superlative. The positive form is "little," the comparative form is "less," and the superlative form is "least." These forms are used to express varying degrees of smallness or quantity.
Positive, comparative, and superlative
A superlative.
The degree of comparison is superlative. Descriptive words ending with -est are superlative forms.
The degree of comparison is superlative. Descriptive words ending with -est are superlative forms.
Longest is the superlative form.
Sleepier is the comparative for sleepy. Sleepiest is the superlative.
Superlative
Comparative: cooler or less cool (depending on the comparison) Superlative: coolest
The degree of comparison is superlative.