(Latin: suffix; able manner, capably)

Forming adverbs corresponding to adjectives in -able.

inexplicably (adverb), more inexplicably, most inexplicably
Pertaining to how something is impossible of being accounted for or explained: Right in the middle of the concert Joan's brother suddenly and inexplicably disappeared, but later he explained why.
inheritably (adverb) (not comparable)
Descriptive of how something can be acquired or received: It is inheritably probable that Hana got her lovely brown eyes from her mother, but not from her father, who had blue eyes.
inhospitably (adverb), more inhospitably, most inhospitably
Conveying how a behavior is unfriendly or unkind: Sam's new family welcomed him inhospitably into their home, but later they tried to explain why they were so insensitiv regarding his arrival.
innumerably (adverb), more innumerably, most innumerably
Concerning how something is too multitudinous or cannot be estimated: Two examples of innumerably excessive numbers would be the countless snow flakes or hail innumerably falling during a winter storm, and the rain drops innumerably precipitating when it rains.
insatiably (adverb), more insatiably, most insatiably
1. Descriptive of how a desire is unquenchable or impossible to appease: Mary was insatiably curious about the universe and was forever reading books regarding the cosmos.
2. Relating to how something is done with steadfastness, but lacking fulfilment or pleasure: Clint seemed to be insatiably hungry for more and more lovemaking with his girlfriend, but she didn't feel the same in return and felt suffocated.
inseparably (adverb), more inseparably, most inseparably
Pertaining to the incapability of being divided or separated: Lynn's life is inseparably connected to her two daughters and their families and the loving relationship will last forever!
insolvably (adverb), insolvably, most insolvably
Pertaining to how something cannot be explained or figured out: The issue seemed to be insolvably complicated and difficult, so the members of the staff decided to move on to the next item on the agenda.
insufferably (adverb), more insufferably, most insufferably
Concerning how something is too unpleasant, or too difficult, to accept: As a patient, Laura's insufferably arrogant attitude towards the medical staff at the hospital made it very difficult for them to provide her with the care that she needed.
insuperably (adverb), more insuperably, most insuperably
Pertaining to how something is impossible to overcome or to solve: Jack was overwhelmed with the many insuperably difficult and mandatory classes he had to take during his first year in college!
insupportably (adverb), more insupportably, most insupportably
A reference to how an action is unjustifiable or indefensible: It was an insupportably aggressive act when little Sally pushed a smaller boy on the playground and made him fall down and hurt himself.
insurmountably (adverb), more insurmountably, most insurmountably
1. Descriptive of how something is incapable of being surmounted, passed over, or overcome: Because of many insurmountably demanding problems concerning the upcoming senior prom, the staff decided to postpone it until a later date.
2. Concerning how some physical obstacle is too great to be overcome: The hike to the peak of the very high mountain seemed to be insurmountably difficult and exhausting for Jenny who hadn't had much experience in mountain climbing.
interchangeably (adverb) (not comparable)
Relating to how definitions or expressions can be swapped or switched: During the pandemic, the terms "lockdown" and "shutdown" have been used interchangeably in the news.
interminably (adverb), more interminably, most interminably
Regarding how something goes on unceasingly, tediously, or seemingly endlessly: The interminably long and boring meeting finally concluded just before lunch.
intolerably (adverb), more intolerably, most intolerably
1. A reference to how a situation is impossible to tolerate or endure; unbearably: Mary suffered intolerably with an agony that made her life miserable.
2. Concerning how something is beyond endurance: Last winter was intolerably cold, then the summer was intolerably hot and dry.

The road work outside Tom's house was intolerably deafening and nerve-wracking!

intractably (adverb), more intractably, most intractably
1. Concerning how an illness or problem is hard to deal with; unmanageably: The ailment that Martin had was intractably stubborn in healing and took various medications to get it under control.
2. Pertaining to how some people are obstinate or uncontrollable: Tony's sister was so uncooperative, cantankerous, and seemingly intractably difficult at times.