IPA: /ˈkɒmənli/
KK: /ˈkɑːmənli/
In a way that happens often or is usual.
People commonly use smartphones for communication.
Commonly → It is formed from "common" (from Old French *comun*, meaning shared by all) and "-ly" (meaning in a manner of). The word "commonly" means in a manner that is shared by all or frequently occurring.
Think of something that is 'shared by all' ('common') and how it happens 'in a manner' ('-ly'). This helps you remember that 'commonly' refers to something that happens frequently or is widely accepted.