The difference between Common and Usual

When used as adjectives, common means mutual, whereas usual means most commonly occurring.

Common is also noun with the meaning: mutual good, shared by more than one.

Common is also verb with the meaning: to communicate (something).

check bellow for the other definitions of Common and Usual

Common as an adjective:

Mutual; shared by more than one.

Examples:

"The two competitors have the common aim of winning the championship."

"Winning the championship is an aim common to the two competitors."
Common as an adjective:

Occurring or happening regularly or frequently; usual.

Examples:

"It is common to find sharks off this coast."
Common as an adjective:

Found in large numbers or in a large quantity.

Examples:

"Sharks are common in these waters."
Common as an adjective:

Simple, ordinary or vulgar.
Common as an adjective (grammar):

In some languages, particularly Germanic languages, of the gender originating from the coalescence of the masculine and feminine categories of nouns.
Common as an adjective (grammar):

Of or pertaining to common nouns as opposed to proper nouns.
Common as an adjective:

Vernacular, referring to the name of a kind of plant or animal, i.e., common name vs. scientific name.
Common as an adjective (obsolete):

Profane; polluted.
Common as an adjective (obsolete):

Given to lewd habits; prostitute.

Common as a noun:

Mutual good, shared by more than one.
Common as a noun:

A tract of land in common ownership; common land.
Common as a noun:

The people; the community.
Common as a noun (legal):

The right of taking a profit in the land of another, in common either with the owner or with other persons; so called from the community of interest which arises between the claimant of the right and the owner of the soil, or between the claimants and other commoners entitled to the same right.

Common as a verb (obsolete):

To communicate (something).
Common as a verb (obsolete):

To converse, talk.
Common as a verb (obsolete):

To have sex.
Common as a verb (obsolete):

To participate.

Examples:

"rfquotek Sir Thomas More"
Common as a verb (obsolete):

To have a joint right with others in common ground.

Examples:

"rfquotek Johnson"
Common as a verb (obsolete):

To board together; to eat at a table in common.

Usual as an adjective:

Most commonly occurring; typical.

Examples:

"The preference of a boy to a girl is a usual occurrence in some parts of China."

"It is becoming more usual these days to rear children as bilingual."