This document contains a list of words beginning with the prefixes "ir-", "im-", "un-", and "il-", many of which are negative in connotation and refer to things that are not possible, permissible, or desirable. The words describe states of being such as unhappy, unlucky, unnecessary, unforgivable, immature, impatient, illiterate; actions that are illegal, illogical, illegible, irrational, irregular, irrelevant, irresponsible, or irreparable; and qualities of being immortal or immobile.