* in-: This is the most common prefix, meaning "in," "into," "on," "upon," or "not."
* include (to take in)
* incorporate (to form into a body)
* invade (to enter by force)
* insomnia (lack of sleep)
* im-: This is used before words that begin with "m" or "p."
* impossible (not possible)
* immature (not mature)
* impede (to hinder)
* il-: This is used before words that begin with "l."
* illegal (not legal)
* illiterate (not literate)
* illogical (not logical)
* ir-: This is used before words that begin with "r."
* irrelevant (not relevant)
* irresponsible (not responsible)
* irresistible (unable to be resisted)
These are just a few examples; there are many more words that use the root "in" in Latin.