Answer:
The prefix “ir-”
Explanation:
Prefixes are letters or syllables placed at the beginning of a word to modify that word's meaning. The prefix “ir-” is one usually added to some adjectives and nouns that begin with the letter “r”. It can mean “in” or “into,” such as in the word “irradiation,” or “not” or “no” such as in the words “irresponsible,” “irregular,” “irrational” and “irreplaceable.”
