Introduction:

When something is described as the extreme of something we use a superlative.

Structure:

For one syllable use est
e.g. newest (for the inferior you say the least new)
For two syllables use the most / least
Exceptions best, worst

Examples:

That is the best team.
That is the easiest project.
They are the most interesting group.
Remember (farthest = physical space, furthest = figurative space)
It is the farthest destination. \ It is the furthest from the truth.