It can be used as an adjective (e.g., "l'anglais est une langue difficile" - "English is a difficult language") or as a noun (e.g., "il est anglais" - "he is English").
It can be used as an adjective (e.g., "l'anglais est une langue difficile" - "English is a difficult language") or as a noun (e.g., "il est anglais" - "he is English").