Engine and Ingenuity are easily confused words.
The spell-check application of most word processing software programs would not catch a slip-up of these two words. Spell-check is looking for words that aren’t in its dictionary, and words that resemble words in its dictionary but are possibly spelled wrong. Spell-check isn’t perfect. It doesn’t know and can’t guess what word you wanted or what word you meant, it can only judge the words on the page. If you used words that are all spelled correctly, it gives you a pass anyway.
Autocorrect suggests words that start with the same letters. It suggests what word you may want to save time, but quite often, its suggestions couldn’t be more off base and produces humorous results.
Engine is a noun. It means the heart of a car, a truck, a locomotive, or a boat where thermal energy is converted to mechanical energy to create motion.
Ingenuity is an adjective. Ingenuity is when someone demonstrates inspired skill and originality in bringing a brand new creation to life, or improving a process in a revolutionary way. Henry Ford, Nikolai Tesla, Virginia Apgar, and Ada Lovelace are people you could describe as possessing ingenuity in their fields.
The following story uses both words correctly:
Engla hoped her engine that ran on echinacea seed oil displayed enough ingenuity to win at the science fair.