Impossible means it cannot happen and cannot be done — not merely hard, not unlikely, but shut. Being in two places at once; finishing a three-hour job in ten minutes.
The patterns are impossible TO do something and impossible FOR someone to do it: it was impossible to sleep, impossible for us to get there by six. You can make something impossible as well — the noise made it impossible to think. The noun is impossibility and the adverb is impossibly, which slides into meaning almost unbelievably: impossibly thin, impossibly young. Be careful with people: an impossible person is not one who cannot exist, but someone so difficult that nobody can please them. Spelling trap — im-, not in-, and two s's.
1adjectiveimpossibleUnable to happen or to be done, whatever anyone tries.~98%
“It is impossible to breathe under water without equipment.”
2adjectiveextremelyExtremely difficult to deal with; impossible to please.~2%
“He was in an impossible mood all morning.”
Shares are an estimate: a language model read 6 sentences found in the wild and placed 6 of them on a sense — a count of our sample, not a measurement of English.
Impossible is possible with im- fixed to the front, the same negative prefix that gives imperfect and impatient. English took the whole word over in the Middle Ages, and it has meant not-possible from the start.
Middle English
impossible
English, today
impossible
From Middle English impossible, equivalent to im- + possible.
Etymology from Wiktionary, CC BY-SA