Vietnamese vs Vietnamese language

Vietnamese and Vietnamese language both are nouns.

Word	Noun	Adjective	Verb	Adverb
Vietnamese	Yes	Yes	No	No
Vietnamese language	Yes	No	No	No

As nouns, Vietnamese and Vietnamese language are synonyms defined as:

Vietnamese and Vietnamese language: the Mon-Khmer language spoken in Vietnam

Other synonyms of Vietnamese include Annamese, Annamese language, Annamite, Annamite language.

Vietnamese (noun)	Vietnamese language (noun)
the Mon-Khmer language spoken in Vietnam	the Mon-Khmer language spoken in Vietnam
a native or inhabitant of Vietnam

Vietnamese (adjective)	Vietnamese language (adjective)
of or relating to or characteristic of Vietnam or its people or its language