The adjective form of America is American. The word American can also be a noun (demonym).
Yes, European is a proper adjective that describes a noun as of or from Europe.
No, European is an adjective, the corresponding proper noun is Europe.
The proper adjective for Siam is Siamese.
The proper adjective for George is Georgian.
The proper adjective for Antigua is Antiganantigan
The proper adjective form is European. (It is also the demonym for a person from Europe.)
Yes, European is a proper adjective that describes a noun as of or from Europe.
No, European is an adjective, the corresponding proper noun is Europe.
Middle Eastern is the only proper adjective in the sentence above. It describes "greenhouses."
The proper adjective for Portuguese is "Portuguese."
The proper adjective for southwest is "southwestern."
The proper adjective for Haiti is Haitian.
Vietnamese is the proper adjective for Vietnam.
The proper adjective for Siam is Siamese.
The proper adjective for George is Georgian.
Freudian is the proper adjective for Freud.
The proper adjective for Georgia is Georgian.