French adjectives ending with -issime

When you want to use an adjective in its most or least extreme form, you generally use the superlative. In French this is achieved by using the words plus or moins, although some irregular words have their own superlative forms (more on this in our blog on superlatives).

Another way to express the superlative form of an adjective is by using the intensifying suffix -issime. For example, if you wanted to say 'This coin is extremely rare', you could say either Cette pièce de monnaie est extrêmement rare or Cette pièce de monnaie est rarissime.

Now, there is a slight difference between these expressions. For one, -issime is normally only used with a few adjectives, even if it can technically be appended to any adjective. Below we've listed the key ones, in both their normal form and with the suffix -issime.

The other difference is that -issime is stronger in emphasis, to the point that it can sometimes carry ironic connotations. For instance, if you were to describe un film as excellentissime, people might assume you were being insincere.

Cette plante est rarissime. - This plant is extremely rare.

Ce film est nullissime ! - This film is terrible.

Il est devenu richissime grâce à son entreprise. - He became extremely rich thanks to his company.