To modify something is to change it, improve it, describe it, or make it new.
Our neighbors are modifying their house with a large addition to the kitchen.
Mechanics modified the engine of the car in order to make it go faster.
The entrance of the building is being modified in order to accommodate people in wheelchairs.
Tom modified his lawnmower so that it could cut the grass by remote control.
Any attempt to modify a product you purchase will probably invalidate the warranty. (If you try to change the thing you purchased, you won’t be able to return it to the store.)
An adjective modifies a noun.
An adverb modifies a verb, an adjective, or another adverb.
The word "modified" is an adjective:
He’s riding a modified skateboard that has a small gas-powered engine in the back.
A modified Toyota Supra won the automobile race.
A modified version of the candidates’s speech had a softer, less aggressive tone than the original version.
The company took a modified approach to marketing its products by including more people of color in its TV commercials.
Modifications to this van make it more fun to drive.
The word "modification" is a noun:
We made a few modifications to our kitchen to admit more sunlight.
Modifications made to the robot improved its performance.
Modifications to the operating system of the computer will bring it up to date.
Roger installed some mods to the game so that it was more interesting to play. (The word "mod" is a shortened form of "modification.")
