fromEnglish Grammar Today
We use these prefixes most commonly in negation:de-,dis-,il-/im-/in-/ir-,mis-,non-,un-:
What he said was veryimpolite.
There was amisunderstanding about who should sign the contract.
The refugees also neednon-food items such as tents and blankets.(items which are not food)
-lessis the most common suffix for negation:
Too many people are homelessin this city.
We just have endlessmeetings at work – they’re so boring.
See also:
Prefixes
Suffixes