This is the 189th most frequent Polish word.
mogli
"Could" (past tense, plural form).
This use of 'moglibyśmy' indicates a conditional possibility; it expresses what would have been possible under different circumstances.
Gdybyście przyszli wcześniej, moglibyśmy obejrzeć film.
If you had come earlier, we could have watched the movie.
Here, 'mogliby' expresses a polite or potential request for assistance.
Czy mogliby pomóc nam w organizacji wydarzenia?
Could they help us with organizing the event?
In this sentence, 'mogli' describes a possibility or ability in the past.