We use the + superlative  adjectives to say which is the biggest, etc in a group.

After superlatives we use in + names of places or singular words for groups of people (“It’s the craziest city in the world”. “ Jerry is the youngest in the class”

We can also use the least + adjective (eg: “The least expensive OR the cheapest”

We often use the + superlative with the present perfect + ever.

EXAMPLES:

My town is the cleanest in the city.

Germany is one of the most popular holiday destinations.

Camping is the least expensive way to go on holiday.

It’s the most beautiful picture I’ve ever seen.

It’s the farthest city I’ve visited this year.

BASIC FORMULA:

X + TO BE + THE MOST + ADJECTIVE

English is the most important language.