“Lose” is a verb. It means to misplace something or to not win something.
I better not lose my car keys again.
I predict that the Hurricanes will lose their last hockey game.
“Loose” is an adjective and means something that isn’t tight or it’s free from constraint.
My pants are too loose.
Lethbridge roads are covered in loose gravel leftover from winter road maintenance.
The trick here is similar to that for “too”. “Loose” has an extra O, which implies more room.
