* un-: A prefix meaning "not" or "opposite of".
* inten-: A bound morpheme meaning "to intend" or "purposeful".
* -tion: A suffix meaning "the act of" or "the state of".
* -al: A suffix meaning "relating to" or "characterized by".
* -ly: A suffix meaning "in a manner" or "to a degree".
Therefore, the word "unintentionally" has 5 morphemes.