It was futile to sit up waiting for Santa. Remember: he sees you when you're sleeping.
His attempts to change her mind were futile as she had already made up hers.
Resistance is futile, human. Her wild attempts at explanation were futile.
You take the word 'futile' and combine it with other words, at least one of which should be a verb, using the rules of grammar for the language in question.
Resistance is futile!
Charlotte's effort to stop the car from rolling down the hill was futile. apex
The rescue mission was futile.
We tried to work out the problem but our attempts were futile. Kim told us it was futile to try, because we wouldn't get anywhere. Then Alex said, there's no such thing as futile: anything can be achieved if we really work at it. And Alex was right: it wasn't futile after all. We found four whole sentences that used the word 'futile' five times.
The word "futile" is an adjective.
The bank robbers tried their best to escape the police chasing after them, but their attempt was futile, as they were soon apprehended and thrown in jail.
I am not writing a sentence using that word.
Resistance is futile! The 'hail Mary pass' was a futile attempt to tie the score in the game's final seconds.
Despite their efforts, their attempts to change the outcome were futile.