Answer: tion
Explanation:
A suffix refers to a letter or a group of letters that is added to the ending of a word so that a different or new word is formed.
The suffixes “-tion” is typically used in creating nouns from verbs and it is used in describing an action, condition, state, or process. The the suffix of the words generation, recognition, and devotion is "tion".
Generation is gotten from the verb "generate".
Recognition is gotten from the verb "recognize".
Devotion is gotten from the word " devote".